ArticlePDF Available

Leaf architecture of Rhus s.str. (Anacardiaceae)

October 2009
Feddes Repertorium 120(5‐6):293 - 306

October 2009
120(5‐6):293 - 306

DOI:10.1002/fedr.200911109

Authors:

Universidad Nacional Autónoma de México

A comprehensive leaf architecture study of 31 species of Rhus s.str. was conducted to describe and identify characters of potential value for assessing infrageneric relationships. The first detailed leaf descriptions for Rhus subgenera are provided and show that cleared leaves revealed craspedodromous, eucamptodromous, and cladodromous venation types in the species studied. There was a diversity of terminal idioblasts associated with free simple or branched veinlets, and a unique combination of leaf organization, venation type, terminal idioblasts, and crystals allowed identification of subgenera and sections. Within the genus, species with toothed deciduous compound leaves exhibit a tendency to mostly craspedodromous venation with weakly sclerified tertiary veins and poorly developed terminal idioblasts; species with simple or compound evergreen leaves show mostly eucamptodromous and cladodromous venation with sclerified bundle sheath cells towards fifth-order veins and well-developed terminal idioblasts. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Selected characters of leaf organization and venation features of Rhus s.str. LO = leaf organization, LM = leaf margin, TVP = tertiary veins pattern, IM = intramarginal vein, TTI = type of terminal idioblasts

…

Figures - uploaded by Teresa Terrazas

Content may be subject to copyright.

Content uploaded by Teresa Terrazas

Content may be subject to copyright.

Feddes Repertorium 120 (2009) 5–6, 293–306 DOI: 10.1002/fedr.200911109 Weinheim, Oktober 2009

Colegio de Postgraduados, Programa de Botánica, Montecillo

Universidad Autónoma de Puebla. Escuela de Biología, Puebla

Universidad Nacional Autónoma de México, Instituto de Biología, Departamento de Botánica, México City

A. R. ANDRÉS-HERNÁNDEZ

1, 2

& T. TERRAZAS

Leaf architecture of Rhus s.str. (Anacardiaceae)

With 4 Figures, 3 Tables and one Appendix

Summary

A comprehensive leaf architecture study of 31 spe-

cies of Rhus s.str. was conducted to describe and

identify characters of potential value for assessing

infrageneric relationships. The first detailed leaf

descriptions for Rhus subgenera are provided and

show that cleared leaves revealed craspedodromous,

eucamptodromous, and cladodromous venation types

in the species studied. There was a diversity of

terminal idioblasts associated with free simple or

branched veinlets, and a unique combination of leaf

organization, venation type, terminal idioblasts, and

crystals allowed identification of subgenera and sec-

tions. Within the genus, species with toothed deci-

duous compound leaves exhibit a tendency to mostly

craspedodromous venation with weakly sclerified

tertiary veins and poorly developed terminal idi-

oblasts; species with simple or compound evergreen

leaves show mostly eucamptodromous and cladodro-

mous venation with sclerified bundle sheath cells

towards fifth-order veins and well-developed termi-

nal idioblasts.

Introduction

The genus Rhus has a long taxonomic history.

E CANDOLLE (1825) proposed one of the first

infrageneric classifications, treating Cotinus,

Lobadium, Metopium, Sumac, and Thezera as

sections. E

NGLER (1883) gave the status of ge-

nus to Cotinus and Metopium and grouped all

other Rhus species into four sections: Tri-

chocarpae, based on Rhus coriaria L.; Venena-

tae, which includes the complex Malosma and

Toxicodendron; Gerontogeae which contains

species from Africa and India; and Melanocar-

pae with two species, R. retusa Z

OLL. and

R. simarubaefolia G

RAY. More than 50 years

later, B

ARKLEY (1937) treated Cotinus, Malos-

ma, Metopium, and Toxicodendron as distinct

genera and circumscribed Rhus s.str. into two

subgenera, Sumac and Schmaltzia (Table 1).

Under the influence of the wood anatomy and

pollen morphology study by H

EIMSCH (1940),

ARKLEY (1940, 1942, 1957) segregated Du-

ckera (section Melanocarpae of E

NGLER) and

Searsia (section Gerontogeae of E

NGLER) from

Rhus (Table 1). Following these proposals, va-

rious authors have preferred to recognize the

genus Rhus s.l. (GILLIS 1961; BRIZICKY 1963).

In more recent works, some authors (Y

OUNG

1975; MILLER et al. 2001; YI et al. 2004) have

agreed with the segregation of genera sensu

ARKLEY, as well as with the circumscription

of Rhus s.str. into the subgenera Rhus and

Lobadium, which correspond to Sumac and

Schmaltzia of B

ARKLEY (1937), and have ac-

cepted a smaller number of species.

OUNG (1975) recognized the genus Rhus

s. str. as defined by red or reddish fruits with

glandular trichomes. Ten species are grouped

into the subgenus Rhus: four are distributed in

Eastern Asia, four in North America, one in

Southeastern Europe, and one in Hawaii. Spe-

cies of this subgenus have deciduous impari-

pinnate compound leaves; flowers appear after

leaves and occur in terminal thyrses; and each

flower is subtended by a linear-lanceolate, ca-

ducous bract (B

ARKLEY 1937; YOUNG 1974).

Rhus subgenus Lobadium contains 27 species

OUNG 1975), mainly distributed in the

southwestern United States of America and in

Mexico. Subgenus Lobadium has evergreen or

294 Feddes Repert., Weinheim 120 (2009) 5–6

Table 1

Infrageneric classification of genus Rhus according to various authors

Author Subgenera/sections Segregated genera

DE CANDOLLE (1825) Five sections: Sumac, Lobadium, Cotinus,

Metopium, Thezera

ENGLER (1883) Four sections: Trichocarpae, Venenatae,

Melanocarpae, Gerontogeae

Cotinus, Metopium

ARKLEY (1937) Two subgenera: Sumac, Schmaltzia, with

five sections

Cotinus, Duckera, Malosma,

Metopium, Searsia, Toxicodendron

RIZICKY (1963) Seven subgenera: Lobadium, Malosma,

Metopium, Melanococca, Rhus, Thezera,

Toxicodendron

OUNG (1975) Two subgenera: Rhus, Lobadium, three

sections

ILLER et al. (2001)

I et al. (2004)

Two subgenera: Rhus, Lobadium Cotinus, Duckera, Malosma,

Metopium, Searsia, Toxicodendron

deciduous simple, trifoliate, or compound

leaves; flowers appear before or with the leaves

and group in compound spikes; and each

commonly sessile flower is subtended by a

persistent deltoide or ovoid bract and two

bractlets (B

ARKLEY 1937; YOUNG 1974; 1978).

ILLER et al. (2001) and YI et al. (2004),

based on nuclear and chloroplast sequences,

support the monophyly of B

ARKLEY (1937),

arguing that relationships among species of this

genus are not Rhus s.str. resolved. Although

various authors have documented leaf venation

patterns for several Anacardiaceae members

ICKEY & WOLFE 1975; TERRAZAS-SALGADO

1994; AGUILAR ORTIGOZA et al. 2004; MARTÍ-

NEZ-MILLÁN & CEVALLOS-FERRIZ 2005), few

species of Rhus have been studied. The present

study provides the first detailed descriptions

and interpretation of foliar architecture among

species of Rhus s.str. and emphasizes charac-

ters of potential value for assessing the in-

frageneric circumscription.

Materials and methods

More than 360 specimens with mature leaflets

or leaves representing both Rhus s.str. subgen-

era were investigated (Appendix 1). We remov-

ed 1–7 leaflets or leaves per species from her-

barium specimens (Appendix 1). Blades were

cleared in 5% NaOH at 60 °C for at least 12 hs.

and dehydrated in 50–100% ethanol. Between

96% and 100% ethanol, blades were placed in a

BB-4

1/4

clearing solution (nine parts 4:2:2:1

85% lactic acid:clove oil:xylene:phenol, and

one part benzyl benzoate) for 24 hs to 30 d and

stained with safranin, then destained until a

suitable contrast of venation and background

was attained. Dehydration was followed by

three changes in xylene. Material was mounted

on glass slides in synthetic resin and dried for

several weeks. Whole leaflets or leaves were

photographed with a 35 mm Nikon F3 camera

using T-Max film; higher-order venation was

photographed with a 35 mm Olympus camera

adapted to an Olympus compound light micros-

cope. Terminology follows H

ICKEY (1979). In

this study, three types of terminal idioblasts are

recognized.

Results

Descriptions of each subgenus are presented

below; for R. microphylla, the description fol-

lows that for the whole subgenus Lobadium

section Lobadium in which it is classified. In-

formation in parenthesis following each sub-

genus and section name indicates the number

of species recognized and the number of spe-

cies sampled.

Subgenus Rhus (10/7)

Fig. 1a–c, h–j; Fig. 2a

Petiole 2.5–10.0 cm long. Multifoliate decidu-

ous leaves, with winged rachis except in R. ty-

phina; chartaceous, except membranaceous in

R. coriaria. Leaflets sessile, 1.9–10.3 cm long

A. R. ANDRÉS-HERNANDEZ & T. TERRAZAS: Leaf architecture of Rhus s.str. 295

Fig. 1

Cleared leaflets

a — R. typhina H.

E. AHLES 17709; b — R. sandwicensis HITCHCOCK 14300; c — R. michauxii H. E. AHLES

58816; d — R. trilobata F. L. B

ENNETT s.n.; e — R. aromatica S. ZAMUDIO 3044; f — R. schmidelioides H. A.

WAHLX 17406; g — R. allophylloides R. VEGA 2509; h — R. glabra A. BENITEZ 1417; i — R. lanceolata

ALAZAR s.n.; j — R. copallina SEARMAN 2944; k — R. microphylla S. S. WHITE 4699

Scale bars: a–c, f–h = 1 cm; d, e, i, j = 0.5 cm

296 Feddes Repert., Weinheim 120 (2009) 5–6

Fig. 2

Details of cleared leaves and leaflets

a — R. glabra A.

BENITEZ 1417; b — R. microphylla ANDERSON 4624; c — R. typhina RADFORD 16002; d —

R. terebinthifolia C

ROAT 63933; e — R. jaliscana ORNELAS 1458; f — R. kearneyi MORAN 16308; g — R.

ovata S.

BOYD 6744; h — R. virens WARD 5786; i — R. microphylla ANDERSON 4624; j — R. jaliscana

RNELAS 1458; k — R. kearneyi MORAN 16308; l — R. oaxacana CROAT 46237

Scale bars: all 100 µm, except g, d = 50 µm

and 0.7–3.7 cm wide (Table 2), asymmetric,

ovate, lanceolate, ovate–lanceolate, or ovate–

elliptic; base asymmetric obtuse to rounded;

apex mostly acute with an apical tooth, attenu-

ate in R. copallina and obtuse in R. coriaria

and R. glabra; margin serrate with rosoid teeth

(Fig. 2a) except for R. copallina and most sam-

ples of R. lanceolata with entire margin. Prima-

ry vein moderate, straight. Simple craspedodro-

mous venation, except for R. copallina and

R. lanceolata, which have eucamptodromous

venation. Secondary veins 5–23 (5–7 in R. co-

riaria and 18–23 in R. typhina), curved with

moderate to wide angles of divergence in api-

cal, middle, and base portions, mostly 60°, ex-

cept for R. sandwicensis, R. michauxii, R. ty-

phina, and R. copallina with angles up to 70°–

80°; the wider angles commonly at the base. In-

tersecondary veins compound. Tertiary veins

weakly percurrent, sometimes alternate; tertiary

veins oblique in relation to primary vein, and

origin of tertiary veins with relation to second-

ary veins acute-acute or acute-obtuse (Fig. 1b).

Sclerenchymatous sheathing of primary and

secondary veins to tertiary in part. Highest or-

der of venation mostly 4 and 5, rarely up to 6

in R. sandwicensis; quaternary and quinternary

veins thin with random reticulate course. Are-

oles mostly imperfect–incomplete, but exclu-

sively incomplete in R. michauxii and R. typhi-

na (Fig. 2c). Veinlets simple or once branched

(Fig. 3c, d); terminal veinlets devoid of any

A. R. ANDRÉS-HERNANDEZ & T. TERRAZAS: Leaf architecture of Rhus s.str. 297

Table 2

Characters and character states of Rhus s.str. 1. Petiole size (cm); 2. lamina organization: multifoliolate (m), trifoliolate (t), or simple (si); 3. rachis

winged: absent (a) or present (p); 4. texture: chartaceous (ch), coriaceous (co), or membranaceous (me); 5. petiolule size (mm); 6. lamina length (cm); 7.

lamina width (cm); 8. lamina shape: elliptic (el), lanceolate (la), or ovate (ov); 9. base shape: acute (ac), obtuse (ob), or rounded (ro); 10. apex shape:

acuminate (am), acute (ac), attenuate (at), obtuse (ob), or rounded (ro); 11. margin: entire (e) or serrate (s); 12. primary vein course: straight (st), sinuous

(sn), or curved (cu); 13. venation pattern: simple craspedodromous (cr), mixed craspedodromous (cm), eucamptodromous (eu), or cladodromous (cl); 14.

secondary vein course: zig-zag (zi), sinuous (sn), or curved (cu); 15. tertiary vein pattern: random reticulate (re), weakly percurrent (pe), or ramified

transverse (t); 16. areole development: incomplete (in) or imperfect (im); 17. veinlets tracheoblast type: none (a) or type I (I), II (II), or III (III); 18. intra-

marginal vein: absent (a) or present (p); 19. marginal ultimate venation: incomplete (in), looped (lo), or fimbrial (fi); 20. crystals: dru

ses (d) or prismatic

(P)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Rhus subg. Rhus

R. copallina 3–6 m p ch – 5.3–8.3 1.3–3.0 ov ob at e st eu cu pe in–im a a lo–in d

R. coriaria ? m p me – 1.9–2.8 0.9–1.4 ov–el ob ob s st cr cu pe im–in I a lo–in d

R. glabra 8–11 m p ch – 7.4–10.3 1.8–2.7 ov–la ob ob s st cr cu pe im–in a a lo–in d

R. lanceolata 2.5–3.5 m p ch – 2.4–5.1 1.0–1.2 la ob ac e st cr–eu cu pe im–in a a lo–in d

R. michauxii 8 m p ch – 7.8–9.5 3.1–3.6 ov ro ac s st cr cu pe in a a lo–in d

R. sandwicensis ? m p ch – 3.6–4.8 2.4–3.7 ov ob ac s st cr cu pe im a a lo–in d

R. typhina 6–10 m a ch – 4.2–7.6 0.7–0.9 ov ob ac s st cr cu pe in I a lo–in d

Rhus subg. Lobadium sect. Lobadium

R. aromatica 0.8 t – me – 2.2–3.4 1.9–3.1 ov–el ob ob s st cm cu re im–in I a lo d

R. allophylloides 1.1 t – ch – 3.0–5.7 1.4–3.4 el ob ob s st cm sn re im I a lo d

R. schm

idelioides 1.5 t – ch – 2.4–6.0 1.5–5.8 el ob ob s st cm cu re im–in I a lo–in d

R. trilobata 0.5 t – ch – 1.1–3.5 0.9–2.6 ov–el ob ob s st cm cu re in I a lo d

R. microphylla 0.3 m p ch – 0.4–1.1 0.2–0.4 el ob–ac am e sn eu sn re in–im I a lo–in d

Rhus subg. Lobadium sect. Terebinthifolia

R. barclayi 2.5 m a ch 0.4 2.7–5.7 1.1–2.3 ov ac ac e st eu cu re in–im I a lo d

R. costaricensis 2–3 m a ch 0.5 ? ? ov–el ob ac e st eu cu re in–im I a lo–in d

R. hartmanii 1.5 m a ch 0.2 3.5–4.1 1.3–2.1 el ob ob e st eu cu re in–im I a lo d

R. jaliscana 2 m a ch – 1.0–2.6 0.4–1.3 el ro am e st eu cu re in I a lo d

R. palmeri 1.5 m a ch ? ? ? el ac ob e st eu sn re in–im I a lo d

R. rubifolia 2 m a ch – 3.3 1.8 el ro am e st eu cu re in I a lo–in d

R. terebinthifolia

1–2.5 m a ch – 2.1–5.5 1.6–2.8 ov ob ac e sn eu cu re in–im I a lo d

Rhus subg. Lobadium sect. Styphonia subsect. Styphonia

R. integrifolia 0.5 si – co – 4.2–4.9 2.7 ov ro ro e–s st cr zi t in II p lo–in d–P

R. kearneyi 0.6 si – co – 3.4 2.8 ov ro ro e st cl zi t in II p lo d–P

R. muelleri 0.7 si – co – 3.3–6.9 2.8–4.8 el ro ro e st cl sn t in II p lo d–P

298 Feddes Repert., Weinheim 120 (2009) 5–6

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

R. ovata 1.5–2 si – co – 4.5–5.3 3.3–8.8 el ro ro e st cl zi t im III p lo d–P

R. standleyi – si – co – 3.3 2.2 el ro ro e st cl sn t im II a lo d–P

Rhus subg. Lobadium sect. Styphonia subsect. Composite and Intermedia

R. andrieuxii 1.5 m a co 0.1 4.1 2.7 el ob ob e st eu cu re–t in III p lo P

R. nelsonii 3.1 m a co 0.2 1.6–2.4 0.7–0.8 el ro am e cu eu zi re–t im III p lo P

R. oaxacana 3.2 m a co 0.2 5.6–5.9 3.4–4.4 ov ro am e–s st eu zi re–t in II p fi P

R. pachyrrhachis 1.5 m a co 0.3 1.9–3.5 1.2–1 ov ob am e sn eu zi re–t in–im III a lo P

R. schiedeana 2.5 m a co 0.3 2.1–4.9 1.4–2.2 ov ro am e sn eu –cl zi re–t in III p lo P

R. virens 1.5 m a co 0.2 1.4–4.3 0.7–2.0 ov ob ob e sn eu c

u re–t in III p fi P

R. chondroloma 1–2.5 m p co – 2.5–3.8 1.4–3.0 ov ob ob e st eu zi re–t in–im III p lo P

idioblast (Fig. 3c), except for R. coriaria and

rarely R. typhina with type I idioblasts

(Fig. 3d). Intramarginal vein absent. Marginal

ultimate venation looped–incomplete. Druses

abundant in lower-order veins. Simple acicular

trichomes and capitate glands; R. copallina

with two types of gland, commonly small capi-

tate but also larger ovate.

Subgenus Lobadium section Lobadium (5/5)

Fig. 1d–g, k

Petiole 0.5–1.5 cm (Table 2). Trifoliate deci-

duous leaves, chartaceous, but membranaceous

in R. aromatica. Leaflets sessile, 1.1–6.0 cm

long and 0.9–5.8 cm wide (Table 2), asymmet-

ric or weakly asymmetric, elliptic or ovate–

elliptic; base obtuse; apex obtuse; and margin

serrate with rosoid teeth. Primary vein moder-

ate, straight. Mixed craspedodromous venation.

Secondary veins 5–9 except in R. trilobata

with 2, curved or sinuous with obtuse diver-

gence angles (60°–69°) throughout blade. In-

tersecondary veins compound. Tertiary veins

random reticulate, oblique in relation to prima-

ry vein; origin of tertiary veins in relation to

secondary veins straight–straight. Sclerenchy-

matous sheathing restricted to primary and sec-

ondary veins. Highest-order venation mostly 5,

rarely up to 6 in some samples of R. allo-

phylloides; quinternary veins thin with random

reticulate course. Areoles imperfect–incom-

plete or incomplete. Veinlets simple or once

branched with type I terminal idioblasts. Intra-

marginal vein absent. Marginal ultimate vena-

tion looped, but looped-incomplete in R. schmi-

deliodes. Druses in primary to tertiary veins.

Simple acicular trichomes and capitate glands

abundant (Fig. 3g, h), R. trilobata with fewer

trichomes.

R. microphylla (Fig. 1k) is an exception in

section Lobadium, with a petiole 0.3 cm long.

Multifoliate deciduous leaves, winged rachis;

chartaceous. Leaflets sessile, 0.4–1.1 cm long

and 0.2–0.4 cm wide, asymmetric, elliptic;

base obtuse-acute; apex acuminate with an api-

cal rosoid tooth (Fig. 2b); margin entire. Prima-

ry vein weak, sinuous. Eucamptodromous ve-

nation (Fig. 1k). Secondary veins 3–4, sinuous;

angle of divergence 56°–59° and 62° in the

apical, middle, and base lamina. Intersecondary

veins compound. Tertiary veins random reti-

Table 2 (continued)

A. R. ANDRÉS-HERNANDEZ & T. TERRAZAS: Leaf architecture of Rhus s.str. 299

Fig. 3

Details of cleared leaves and leaflets

a — R. terebinthifolia C

ROAT 63933; b — R. microphylla ANDERSON 4624; c — R. lanceolata SALAZAR s.n.;

d — R. typhina R

ADFORD 16002; e — R. ovata S. BOYD 6744; f — R. andrieuxii M. NEGRETE 7065; g —

R. aromatica M.

N. SEARS 1065; h — R. trilobata BENNETT s.n.

Scale bars: a, g, h = 50 µm, b = 100 µm, c–d = 25 µm

culate, oblique in relation to primary vein; ori-

gin of tertiary veins in relation to secondary

veins acute-straight. Sclerenchymatous sheath-

ing restricted to primary and secondary veins.

Highest-order venation 4; quaternary veins thin

with random reticulate course. Areoles incom-

plete-imperfect. Veinlets simple or once branch-

ed with type I terminal idioblasts (Fig. 3b). In-

tramarginal venation absent. Marginal ultimate

venation looped-incomplete (Fig. 2i). Druses

abundant in mesophyll. Simple acicular tri-

chomes and capitate glands.

Subgenus Lobadium section Terebinthifolia (7/7)

Fig. 4d–f

Petiole 1–2.5 cm (Table 2). Multifoliate decid-

uous leaves, unwinged rachis; chartaceous;

leaflets sessile in R. jaliscana, R. rubifolia,

and R. terebinthifolia or 0.2–0.5 cm (Table 2);

1.0–5.7 cm long and 0.4–2.8 cm wide (Table 2);

symmetric or asymmetric, mostly elliptic, ova-

te, or ovate-elliptic; base obtuse, rounded, or

acute; apex acute, obtuse, or acuminate; margin

entire. Primary vein moderate, straight except-

ing R. terebinthifolia sinuous. Eucamptodro-

mous venation. Secondary veins 5–7, curved

excepting R. palmeri sinuous with angles of di-

vergence obtuse (50°–73°) throughout blade.

Intersecondary veins compound. Tertiary vena-

tion random reticulate, join the intersecond-

aries; oblique in relation to primary vein; origin

of tertiary veins with relation to secondary

veins acute–obtuse. Sclerenchymatous sheath-

ing restricted to primary to tertiary veins. High-

est-order venation mostly 5, rarely up to 6 in

some samples of R. rubifolia; quinternary veins

thin with random reticulate course. Areoles

mostly incomplete–imperfect, few exclusively

incomplete (Fig. 2d, e). Veinlets branched with

type I terminal idioblasts (Fig. 3a). Intramargi-

nal venation absent. Marginal ultimate venation

looped or looped-incomplete (Fig. 2j). Druses

in primary and secondary veins and mesophyll

more abundant in some species, like R. jalis-

cana. Simple acicular trichomes and capitate

glands; R. jaliscana with conspicuous tufts of

trichomes in vein axils (Fig. 2e).

Subgenus Lobadium section Styphonia subsection

Styphonia (5/5)

Fig. 4a–c

Petiole 0.5–2.0 cm long (Table 2), but sessile

in R. standleyi. Simple evergreen, coriaceous

300 Feddes Repert., Weinheim 120 (2009) 5–6

Table 3

Selected characters of leaf organization and venation features of Rhus s.str.

LO = leaf organization, LM = leaf margin, TVP = tertiary veins pattern, IM = intramarginal vein, TTI = type

of terminal idioblasts

Taxon LO LM Venation type TVP IM TTI Crystals

Rhus subg. Rhus multifoliolate toothed simple craspedodromous

eucamptodromous

weakly

percurrent

absent none,

druses

Rhus subg.

Lobadium sect.

Lobadium

trifoliolate,

multifoliolate

toothed,

entire

mixed craspedodromous,

eucamptodromous

random

reticulate

absent I druses

Rhus subg.

Lobadium sect.

Terebinthifolia

multifoliolate entire eucamptodromous random

reticulate

absent I druses

Rhus subg.

Lobadium sect.

Styphonia subs.

Styphonia

simple entire,

toothed

cladodromous,

craspedodromous

ramified

transverse

present,

absent

II, III druses,

prismatic

Rhus subg.

Lobadium sect.

Styphonia subs.

Composita

multifoliolate entire eucamptodromous,

cladodromous

random

reticulate,

ramified

transverse

present III, II prismatic

Rhus subg.

Lobadium sect.

Styphonia subs.

Intermedia

multifoliolate entire eucamptodromous random

reticulate,

ramified

transverse

present III prismatic

leaves. Blade 3.3–6.9 and 2.2–8.8 cm wide

(Table 2); symmetric, elliptic, or ovate; base

weakly asymmetric rounded; apex rounded;

margin entire, except for R. integrifolia serrate

with rosoid teeth. Primary vein moderate,

straight. Cladodromous venation except for

R. integrifolia with simple craspedodromous

venation. Secondary veins 7–9, mostly zigzag

or sinuous with obtuse angles of divergence

(50°–70°) throughout blade, but R. standleyi

with narrower angles of divergence 50°, 33°,

and 48° in the apical, middle, and basal blade,

respectively. Intersecondaries compound. Ter-

tiary venation transverse ramified; tertiary

veins oblique in relation to primary vein; origin

of tertiary veins in relation to secondary veins

acute–obtuse. Sclerenchymatous sheathing re-

stricted to primary to fourth-order veins. High-

est-order venation 4 or 5. Quarternary veins

thin with random reticulate course in R. kear-

neyi and R. integrifolia; quinternary veins with

random reticulate course in R. muelleri and

R. ovata, and orthogonal reticulate in R. stand-

leyi. Areoles mostly incomplete, a few imper-

fect (Fig. 2f, g). Veinlets branched with type II

terminal idioblasts except R. ovata with type III

(Fig. 3e). Intramarginal venation present except

for R. standleyi. Marginal ultimate venation

looped or looped-incomplete in R. integrifolia

(Fig. 2k). Druses and prismatic crystal in major

veins. Simple acicular trichomes scarce and

capitate glands.

Subgenus Lobadium section Styphonia subsection

Composita (8/6) and subsection Intermedia (1/1)

Fig. 4g–l

Petiole 1.5 cm long in most species to 3.2 cm

in R. oaxacana. Multifoliate evergreen, cori-

aceous leaves with winged rachis only in

R. chondroloma; leaflets with petiolule 0.1–

0.3 cm long, 1.4–5.9 cm long and 0.7–4.4 cm

wide (Table 2); symmetric or asymmetric,

commonly ovate or elliptic; base obtuse or

rounded; apex acuminate or obtuse; margin en-

tire except for few specimens of R. oaxacana

serrate with rosoid teeth. Primary vein moder-

ate, straight, sinuous, or curved. Eucampto-

dromous venation, except for some samples of

R. schiedeana with cladodromous venation.

Secondary veins 7–9, except in R. schiedeana

with 10–15, zigzagged or curved in R. andrieu-

A. R. ANDRÉS-HERNANDEZ & T. TERRAZAS: Leaf architecture of Rhus s.str. 301

Fig. 4

Cleared leaves and leaflets

a — R. standleyi S

TONE 2785; b — R. muelleri HINTON et al. 24937; c — R. kearneyi MODSON 6979;

d — R. rubifolia R.

ORNELAS 1388; e — R. terebinthifolia CONTRERAS 10464; f — R. jaliscana PRINGLEI s.n.;

g — R. schiedeana C.

GUZMÁN 114; h — R. chondroloma SALINAS D. s.n.; i — R. virens LUNDELL 12477;

j — R. nelsonii C

ALÓMICO 7653; k — R. andrieuxii CALZADA 21799; l — R. pachyrrhachis RZEDOWSKI 52479

Scale bars: a–e, g, j, k = 1 cm; f, h, i, l = 0.5 cm

302 Feddes Repert., Weinheim 120 (2009) 5–6

xii and R. virens; angles of divergence obtuse

(60°–80°), wider at the base of the blade. Inter-

secondary veins compound. Tertiary veins ran-

dom reticulate and transverse ramified. Tertiary

veins oblique in relation to primary vein; origin

of tertiary veins in relation to secondary veins

acute-acute or acute–obtuse. Highest-order ve-

nation 5 with random reticulate course. Areoles

incomplete-imperfect or imperfect (Fig. 2h).

Veinlets branched with type III terminal idi-

oblasts (Fig. 3f), except for R. oaxacana with

type II. Intramarginal venation present except

for R. pachyrrachis. Marginal ultimate vena-

tion looped, except for R. oaxacana and

R. virens with fimbrial vein (Fig. 2l). Prismatic

crystal in primary and secondary veins. Simple

acicular trichomes scarce and capitate glands.

Discussion

Leaf blades of the genus Rhus s.str. exhibit a

diversity of shapes and venation patterns. Most

blades share a common morphology but with

various deviations from the standard that

distinguish the subgenera (Table 3). Blades of

subgenus Rhus are deciduous imparipinnate

compound with sessile serrate leaflets. In addi-

tion, the largest leaflets belong to this subge-

nus. Venation is distinctively simple craspe-

dodromous with the typical rosoid teeth

ICKEY & WOLFE 1975), richly vascularized.

However, there is a transition to loss of the

teeth in R. lanceolata. Various specimens of

this species, like R. copallina, were clearly eu-

camptodromous. H

ARDIN (1992) also noted

few teeth above the middle lamina in R. copal-

lina. In subg. Rhus, species are distinctive,

possessing mostly tertiary veins that are weak-

ly percurrent, slender minor veins, and a lack

of terminal idioblasts in the simple or once

branched veinlets. R

AMIREZ & CEVALLOS-

ERRIZ (2002) describe percurrent tertiary

veins for R. glabra. When tertiary veins origi-

nate, they never join with the opposite tertiary

veins, commonly becoming slender and divi-

ding and forming a reticulum. We interpret this

phenomenon to be related to the absence of

sclerenchyma sheathing of the vascular bundle

in minor veins, which prevents us from obser-

ving the reticulate pattern at low magnification.

The term “weakly percurrent tertiary” is thus

adopted here. In addition, R. copallina, R. mi-

chauxii, R. sandwicensis, and R. typhina shared

the widest angles of divergence in the seconda-

ry veins of all members of Rhus s.str.

Members of subg. Lobadium are highly va-

riable in leaf organization and venation types

but distinctive for their veinlets with terminal

idioblasts (Table 3). Terminal idioblasts associ-

ated with veinlets have been described for vari-

ous families, including the Anacardiaceae (T

U-

CKER

1964; LESTER & CARVEY 1974; RAO &

NASYAK 1987; TERRAZAS-SALGADO 1994; DI-

CKISON

2000; LUCKOW 2002). We recognized

three types of terminal idioblasts and termed as

type I those with only one to two tracheoidal

elements shorter and wider than conventional

vascular elements; type II were those with more

abundant tracheoidal elements; and type III

were those with abundant tracheoidal elements

associated with terminal brachysclereids com-

monly occluded with dark-stained deposits

(Fig. 3).

Species of section Lobadium have trifoliate

laminas with mixed craspedodromous venation

and type I terminal idioblasts. Rhus microphyl-

la was placed in this section based on its wood

with narrow vessels in latewood and resin ca-

nals, in addition to distinctive flavonoids

EIMSCH 1940; YOUNG 1978, 1979). Con-

sistent with our results, this species shares a

few leaflet features such as type I terminal idi-

oblasts with the other four species of this secti-

on. Rhus microphylla is the only species of this

group with compound leaves, leaf with entire

margin, eucamptodromous venation, and a weak,

sinuous primary vein. The recognition of this

species in its own section as proposed by B

ARK-

LEY (1937) must await additional evidence.

Multifoliate leaves, a typical eucamptodro-

mous venation pattern, and type I terminal

idioblasts were found to characterize sect. Te-

rebinthifolia. Compound leaves are also shared

with species of sect. Styphonia subsect. Com-

posita and Intermedia, as well as subg. Rhus,

but they differ in venation pattern and terminal

idioblast type. Moreover, leaf organization, ve-

nation type, weakly sclerified bundle sheath

cells, and terminal idioblast type I are shared

with various species of the Spondiadeae tribe

ERRAZAS, unpubl. data).

OUNG (1979) considers the members of

sect. Styphonia to be the most derived in Rhus

A. R. ANDRÉS-HERNANDEZ & T. TERRAZAS: Leaf architecture of Rhus s.str. 303

s.str. and we agree. The section is distinctive

for its types II and III terminal idioblasts, major

and minor veins (fifth order) with a scleren-

chymatous sheath, and exclusively prismatic

crystals associated with veins. Higher sclerifi-

cation of the bundle sheath cells in members of

this section is correlated with evergreen leaf

condition. Because crystal shape is genetically

fixed (although its abundance may vary in rela-

tion to soil features), prismatic crystals in this

section may be also considered informative for

distinguishing the species of this section from

those of other sections of subg. Lobadium and

subg. Rhus, which mainly have druses (F

RAN-

CESCHI

& HORNER 1980).

Our results support Y

OUNG’S (1979) recog-

nition of subsections in section Styphonia. Spe-

cies of subsect. Styphonia have simple ever-

green leaves with type II terminal idioblasts,

while members of subsect. Composita and In-

termedia have evergreen compound leaves and

terminal idioblasts with brachysclereids. Rhus

andreuxii and R. nelsonii, considered syno-

nymies of R. schiediana and R. oaxacana by

OUNG (1975), share the diagnostic leaf char-

acteristics mentioned for section Styphonia and

subsections Composita and Intermedia and

should be classified here.

ICKEY & WOLFE (1975) stated that Ana-

cardiaceae have pinnately compound leaves

with a mainly eucamptodromous venation type;

however, brochidodromous, cladodromous, and

craspedodromous venation types have also

been reported for this family (T

ERRAZAS-SAL-

GADO 1994; MARTÍNEZ-MILLÁN & CEVALLOS-

ERRIZ 2005). Moreover, compound leaves

with entire margin and incomplete areole devel-

opment have been found in genera of Spondi-

adeae and are considered plesiomorphic for the

family (T

ERRAZAS-SALGADO 1994; KONGKAN-

DA 1997). Here we recognize these three char-

acter states in various species of Rhus, suggest-

ing that they originated independently at

different times within the Anacardiaceae.

Although to support the infrageneric rela-

tionships we need to test in a cladistic analysis

the usefulness of the characters recognized

here, it appears that there is a trend leading

from species with deciduous compound leaves,

craspedodromous with poorly sclerified sheath

cells, and devoid of terminal idioblasts towards

species with evergreen simple or compound

leaves, eucamptodromous or cladodromous

with intramarginal or fimbrial vein, sclerified

sheath cells to fifth-order veins, and type III

terminal idioblasts.

Acknowledgements

We are grateful with curators of ANSM, ARIZ,

DUKE, GH, IEB, IBUG, NCU, NY, TEX, US for al-

lowing us to remove material for this study. The sen-

ior author thanks Consejo Nacional de Ciencia y

Tecnología for a scholarship (169599) supporting

her doctoral studies. Thanks are also extended to

Tom Wendt for sharing his knowledge of Rhus and

to Héctor Hernández for darkroom assistance.

References

AGUILAR-ORTIGOZA, C. J.; SOSA, V. & ANGELES, G.

2004: Phylogenetic relationships of three genera

in Anacardiacee: Bonetiella, Pseudosmodingium,

and Smodingium. – Brittonia 56: 169–184.

ARKLEY, F. A. 1937: A monographic study of Rhus

and its immediate allies in North and Central

America, including the West Indies. – Ann.

Mont. Bot. Gard. 24: 256–500.

ARKLEY, F. A. 1940: Schmaltzia. – Amer. Mid. Nat.

24: 647–665.

ARKLEY, F. A. 1942: A key to the genera of the

Anacardiaceae. – Amer. Mid. Nat. 28: 465–474.

ARKLEY, F. A. 1957: Generic key to the sumac

family (Anacardicaeae). – Lloydia 20: 255–265.

RIZICKY, G. K. 1963: Taxonomic and nomencla-

tural notes on the genus Rhus (Anacardiaceae). –

J. Arnold Arbor. 44: 60–80.

DE CANDOLLE, A. P. 1825: Prodromus systematis

naturalis regni vegetabilis. Vol. 2. – Paris.

ICKISON, W. C. 2000: Integrative Plant Anatomy. –

San Diego.

NGLER. A. 1883: Anacardiaceae. – In A. & C. DE

CANDOLLE (ed.). – Monographiae Phanerogama-

rum 4: 536–540.

RANCESCHI, V. R. & HORNER JR., H. T. 1980:

Calcium oxalate crystals in plants. – Bot. Rev.

46: 361–427.

ILLIS, W. T. 1971: The systematics and ecology of

poison-ivy and the poison-oaks (Toxicodendron,

Anacardiaceae). – Rhodora 73: 793–796.

ARDIN, J. W. 1992: Foliar morphology of the

common trees of North Carolina and adjacent

states. – Technical Rep. 298, N. C. Agri. Res.

Serv. – Raleigh.

EIMSCH, C. J. R. 1940: Wood anatomy and pollen

morphology of Rhus and allied genera. – J.

Arnold Arbor. 3: 279–289.

ICKEY, L. J. 1979: A revised classification of the

architecture of dicotyledonous leaves: 25–39. –

304 Feddes Repert., Weinheim 120 (2009) 5–6

In: C. R. METCALFE & L. CHALK (eds.), Anatomy

of the Dicotyledons. Vol. 1. – Oxford.

ICKEY, L. J. & WOLFE, J. A. 1975: The bases of

angiosperm phylogeny: vegetative morphology.

– Ann. Mo. Bot. Gard. 62: 538–589.

OLMGREN, P. K.; KUEKEN, W. & SCHOFIELD, E. K.

1981: Index Herbariorum. Part 1. Herbaria of the

World. 7

ed. – The Hague.

ONGKANDA, CH. 1997: Molecular phylogenetic of

Anacardiaceae in Thailand. – Thai Forest Bull.,

Bot. 25: 1–13.

ESTER, N. R. & CARVEY, K. A. 1974: Leaf anatomy

of ocotillo (Fouquieria splendens; Fouquieri-

aceae), especially vein endings and associated

veinlet elements. – Canad. J. Bot. 52: 2017–

2021.

UCKOW, M. 2002: Anatomical features of the leaves

in the Dichrostachys group (Leguminosae:

Mimosoideae) and their utility for phylogenetic

studies. – Syst. Bot. 27: 29–40.

ARTÍNEZ-MILLÁN, M. & CEVALLOS-FERRIZ, S. R. S.

2005: Arquitectura foliar de Anacardiaceae. –

Rev. Mex. Biodiv. 76: 137–190.

ILLER, A. J.; YOUNG, D. A. & WEN, J. 2001:

Phylogeny and biogeography of Rhus (Anacar-

diaceae) based on ITS sequence data. – Int. J. Pl.

Sci. 162: 1401–1407.

AMÍREZ, J. L. & CEVALLOS-FERRIZ, S. R. S. 2002: A

diverse assemblage of Anacardiaceae from Oli-

gocene sediments, Tepexi de Rodríguez, Puebla,

México. – Amer. J. Bot. 89: 535–545.

AO, T. A. & NAYAK, P. 1987: The role of vein

termini idioblasts as an aid in the systematics of

Pternandra J

ACK. (Melastomataceae). – Bull.

Bot. Surv. India 29: 181–194.

ERRAZAS-SALGADO, T. 1994: Wood anatomy of the

Anacardiaceae: ecological and phylogenetic

interpretation. – Univ. North Carolina, Chapel

Hill, Ph.D. thesis.

UCKER, S. C. 1964: The terminal idioblasts in

magnoliaceous leaves. – Amer. J. Bot. 51: 1054–

1062.

I, T.; MILLER, A. & WEN, J. 2004: Phylogenetic and

biogeographic diversification of Rhus (Anacar-

diaceae) in the Northern Hemisphere. – Mol.

Phyl. Evol. 33: 861–879.

OUNG, D. A. 1974: Comparative wood anatomy of

Malosma and related genera (Anacardiaceae). –

Aliso 2: 133–146.

OUNG, D. A. 1975: Systematics of Rhus subgenus

Lobadium section Styphonia. – Claremont Grad-

uate School, Claremont, Ph.D. thesis.

OUNG, D. A. 1978: Re-evaluation of the sections of

Rhus L. subgenus Lobadium (R

AF.) T. & G.

(Anacardiaceae). – Brittonia 4: 411–415.

OUNG, D. A. 1979: Heartwood flavonoids and the

infrageneric relationships of Rhus (Anacardi-

aceae). – Amer. J. Bot. 66: 502–510.

Addresses of the authors:

R. Andrés-Hernández, Programa de Botánica,

Colegio de Postgraduados. Montecillo, Estado de

México, 56230 México;

Present address: Universidad Autónoma de Puebla.

Escuela de Biología, edificio 76, Benemérita, Ciudad

Universitaria, C. P. 72570. Puebla, Estado de Puebla,

México

E-mail: arahdm@yahoo.com.mx

Teresa Terrazas, author for correspondence:

Universidad Nacional Autónoma de México, Insti-

tuto de Biología, Departamento de Botánica, Apar-

tado Postal 70-633. México DF, 04510, México

E-mail: tterrazas@ibiologia.unam.mx

Manuscript received: July 3

, 2009.

Appendix 1

Species of Rhus s.str. investigated with information

about collector and voucher location. Abbreviations

of herbaria according to H

OLMGREN et al. (1981)

* indicates those blades that were cleared

Rhus subg. Rhus

Rhus copallina L.: H. E. A

HLES 31816*, NCU; F. A.

ARKLEY 13597, TEX; L. BASTIAN s.n.*, NCU;

R. C

URRIE 884, IBUG; L. H. DO & W. C. HOLMES

226, TEX; W. C. H

OLMES 5454, TEX; B. JENNING 31,

IBUG; A.

A. LUNDELL 9565, 11542, TEX; C. L. LUN-

DELL

11818, TEX; E. G. MORSH JR. 242, TEX; W. D.

SEAMAN 2944*, NCU; A. THOMPSON 2594, IEB; F. R.

ALLER et al. 2806, TEX.

Rhus coriaria L.: I.

AMDURSKI 550*, US; F. G.

MEYER s.n., US; K. H. RECHINGER 31176, US.

Rhus glabra L.: H. E. A

HLES 15244*, NCU; A. BE-

NITEZ 1417*, ANSM; CHESTER & M. ROWELL 4175,

10255b, TEX; D. S. C

ORRELL & H. B. CORRELL

30047, TEX; H. S. GENTRY 306, TEX; R. MCVAUGH

8347, TEX; J. MORGAN 1551*, NCU; S. RODRÍGUEZ

1511*, IEB.

Rhus lanceolata A.G

RAY ex ENGL.: F. A. BARKLEY

3470, ANSM; M.

A. CARRANZA C-3061*, ANSM;

CASTILLO 512, ANSM; A. CHOSE 5961, TEX; D. S.

CORRELL 15098, 38069, TEX; W. COULD 8398, TEX;

GONZÁLEZ 17227, 17571, ANSM; L. C. HINCKLEY

s.n., TEX; H

INTON et al. 21234, IEB; A. POWELL &

S. P

OWELL 3783, TEX; F. SALAZAR s.n.*, US;

ÁZQUEZ-ALDAPE s.n.*, ANSM; J. A. VILLAREAL

6944*, IEB; J. A. VILLAREAL et al. 8876*, ANSM;

A. WORNOCK 9303, 10967, TEX.

Rhus michauxii S

ARG.: H. E. AHLES 58816*, NCU;

H. H. BARTLETT 2881, TEX; W. B. FOX & R. K. GOD-

FREY

4230, TEX.

Rhus sandwincensis A.G

RAY: O. DENEGER s.n.,

TEX; A. S. H

ITCHCOOK 14300*, NCU; H. MANN &

A. R. ANDRÉS-HERNANDEZ & T. TERRAZAS: Leaf architecture of Rhus s.str. 305

W. T. BRIGHAM 412, TEX; P. D. PALMER 30024, NY;

F. ROCK 5837, TEX.

Rhus typhina L.: H.

E. AHLES 17709*, NCU; G. M.

BAKER 555, TEX; S. F. BLAKE 1093, 1984, 3146,

4234, TEX; B.

HAUSEN & M. NEE 3874, TEX; A. E.

RADFORD 16002*, NCU; J. D. STEVENSON 8640,

TEX; H.

R. TOTTENS s.n.*, NCU; H. MALDENKE

25982, TEX.

Rhus subg. Lobadium sect. Lobadium

Rhus allophylloides S

TANDL.: C. CHÁVEZ 4999,

IBUG; M.

CHÁZARO et al. 911, IEB; R. CUEVAS &

ROSALES 1711, IEB; R. GUZMÁN 29089, IEB; HIN-

TON

et al. 2317*, US; J. A. MACHUCA 7726, IBUG;

M. M

ACIAS & B. ARBAYO 633, IBUG; R. ORNELAS

1386, IBUG; A. VÁZQUEZ 3773, IBUG; R. VEGA

2509*, IBUG.

Rhus aromatica A

IT.: H. E. AHLES 27466*, NCU;

W. T. B

AKER 2565*, NCU; E. BAUFFORD 17799,

NCU; D. S. C

ORELL 16214, TEX; D. S. CORELL &

L. LUNDELL 18796, TEX; T. B. CROAT 17119*,

NCU; G

ÓMEZ DURÁN s.n., IEB; HINTON et al. 25181,

IEB; H

INTON et al. 22643, 24072, ANSM; C. L.

LUNDELL & A. A. LUNDELL 9474, TEX; M. NEE

44041, TEX; D. J. SOPER 8950*, NCU; B. C. THORP

2908, TEX; C. TURNER 9, TEX; H. A. WAHLX 17406*,

NCU.

Rhus microphylla E

NGELM.: C. ANDERSON 4629*,

DUKE; M.

CARRANZA et al. 566, 1302, 1341, ANSM;

A. ENCINA 839, ANSM; FLORES MACIAS 1675, IEB;

INTON et al. 16560, 18708, 21896, 21968*, 25346,

25704, 25712, IEB; H

INTON et al. 27549, ANSM;

CHOA MARTÍNEZ 248, IEB; R. PÉREZ 612, ANSM;

J. A. R

EYES 415, IEB; A. RODRÍGUEZ &

M. A. CARRANZA 874, ANSM; RZEDOWSKI 41071*,

41085, 43470, 47060, IEB; P.

TENORIO & C. ROMERO

T. 6406, 13615, IEB; R. VÁZQUEZ 259*, IEB,

ANSM; E. VENTURA 90204*, IEB; E. VENTURA &

E. LÓPEZ 6817, 6824, IEB; J. A. VILLAREAL &

M. A. C

ARRANZA 5218, ANSM; S. S. WHITE 4699*,

DUKE; S.

ZAMUDIO 11085, IEB.

Rhus schmidelioides S

CHLTDL.: H. DÍAZ-BARRIGA

3516*, 3850*, IEB; E.

GONZÁLEZ 408, 634, IEB;

V. M. H

UERTA 521, IEB; C. MEDINA 1652, IEB;

R. O

RNELAS & A. FLORES MACIAS 1371, 1372, 1378,

1397, IEB;

S. S. REYNOSO 1217*, IBUG; RZEDOWSKI

45608*, IEB; H. RUBIO 1554, 609, IEB; SOTERO SER-

VIN

56, IEB; S. ZAMUDIO 2430, 10642, IEB.

Rhus trilobata N

UTT.: F. A. BARKLEY et al. 3739,

ANSM; A.

BENÍTEZ 1443, IEB; F. L. BENNETT s.n.*,

NCU; M.

A. CARRANZA 1482, ANSM; M. A. CARRAN-

1867, IEB; D. CASTILLO & J. M. AGUILERA 849,

ANSM; F.

A. ENCINA et al. 562, ANSM; J. ELIZONDO

& R. BANDA 266, ANSM; L. HERNÁNDEZ 2086*, IEB;

MARROQUÍN 2271, ANSM; S. MARTÍNEZ 74, IBUG;

RODRÍGUEZ 261, IEB; D. A. STEVENS 2413*, NCU;

P. T

ENORIO & C. ROMERO 6491, 1126, IEB; M. N.

SEARS 1065*, NCU; J. A. VILLAREAL 3742, 3949, IEB;

J. A. V

ILLAREAL 1537, ANSM; S. ZAMUDIO 2760,

2854, 3044*, IEB.

Sect. Terebinthifolia

Rhus barclayi S

TANDL.: R. CUEVAS & M. ROSALES

1823, IBUG; R. DELGADILLO et al. 1109, IEB;

S. G

UERRERO 247, IBUG; A. GUZMÁN et al. 977,

IBUG; R. O

RNELAS 1604*, 1614, IBUG; R. ORNELAS

et al. 1506, 1585, IBUG; E.

PALMER s.n.*, US;

F. S

ANTANA et al. 4307*, IEB.

Rhus costaricensis R

ILEY: W. T. GILLIS 9100, 9597,

TEX; T

ONDUZ 9823*, US.

Rhus hartmanii

F.A.BARKLEY: M. FISHBEIN et al.

102a, 121, ARIZ; H.

S. GENTRY 3682, ARIZ; C. H.

MULLER 3689, GH.; L. J. TOOLIN 310*, 1376*,

ARIZ.

Rhus jaliscana S

TANDL.: R. ACEVEDO et al. 1632,

IEB; M. C

HÁZARO et al. 6743*, IEB; H. DE ALBA &

M. CHÁZARO 10, IEB; E. ESTRADA 8555, IBUG;

A. F

LORES 2422, IEB; A. FLORES & M. CHÁZARO

2531, IEB; M. HUERTA & S. GUERRERO 253, IBUG;

R. O

RNELAS 1429*, IEB; R. ORNELAS & J. GARCÍA

CASTAÑEDA 1656, IEB; C. G. PRINGLEI s.n.*, US;

REYNA 551, IBUG; L. M. VILLAREAL 3176, 7223,

9401, IBUG; F.

ZAPATA 10, IBUG.

Rhus palmeri R

OSE: H. S. GENTRY 5672, 7203, 7296,

GH; P. S. M

ARTIN et al. s.n., TEX; P.C. STANDLEY

et al. 13100*, GH; J.

F. WIENS et al. 93-121, TEX;

R. D. W

ORTHINGTON 7939 TEX.

Rhus rubifolia T

URCZ.: R. ORNELAS 1545*, ANSM;

ORNELAS & A. FLORES 1388*, 1391*, 1392, 1513*,

IEB; R.

ORNELAS & J. A. GARCÍA 1461, ANSM.

Rhus terebinthifolia S

CHLTDL. & CHAM.: W. R.

ANDERSON 4338*, DUKE; BREEDLOVE 12284, 12669,

9676, TEX; R.

CEDILLO 1745*, IEB; E. CONTRERAS

10464*, DUKE; T. B. CROAT 63933*, DUKE; R. S.

FELGER et al. 01-61, 01-663, ARIZ; F. GÓMEZ 296,

IEB; E. GONZÁLEZ 1401*, IEB; L. HARDINSON et al.

112, TEX; A.

HERRERA 56, IEB; HINTON et al. 13526,

TEX; M.

LAVIN et al. 4578, TEX; E. MATUDA 5867,

TEX;

H. RUBIO 1750, IEB; SHILOM TOM 1845*,

4041*, DUKE; S

HILOM TOM 1128, TEX; P. TENORIO

15589, 8489, IEB; F. VENTURA 8111, ANSM; M. VI-

ZCARRA 89, ANSM.

Sect. Styphonia subsect. Styphonia

Rhus integrifolia E

NGL.: A. CARTER & L. KELLOGG

3181, TEX; M. DILLON et al. 1829, TEX; J. L. ELI-

ZONDO

311, ANSM; D. KEIL 13688, TEX; R. MORAN

17211, TEX; S. MYER s.n., TEX; S. B. PARISH 6890,

TEX; P. R

AVEN s.n., TEX; S. N. STEPHENSON 67-

135*, DUKE; W

ALLACE & D. THOMPSON 108, TEX.

Rhus kearneyi F.A.B

ARKLEY: R. S. FELGER 89-47,

TEX; M

ODSON 6979*, NCU; R. MORAN 18308*, US;

ANIEL 2312*, NCU; G. L. WEBSTER 18261, TEX.

Rhus muelleri F.A.B

ARKLEY: HINTON et al. 18082,

19208*, 24937*, 25584, IEB; J. M

ARROQUÍN 3705,

ANSM; K. C. N

IXON 4008, TEX; C. D. PETERSON

306 Feddes Repert., Weinheim 120 (2009) 5–6

1277, TEX; T. F. PETTERSON et al. 7164, TEX;

M. P

OOLE et al. 2476*, IEB; R. F. SMITH M657,

M683, TEX; V. V

ALDEZ 790, ANSM; J. A. VILLA

4787, ANSM; J. A.VILLAREAL 13942*, IEB; J. A.

ILLAREAL et al. 5263, ANSM; S. ZAMUDIO et al.

6220, IEB.

Rhus ovata S.W

ATSON: E. K. BALLS 18951, TEX;

BOYD 6744*, NY; M. DOMÍNGUEZ 2236, IEB; H. S.

GENTRY 8979*, US; K. MURATA & E. LEE 20, TEX;

K. C. N

IXON 960*, IEB; S. B. PARISH 6802, TEX;

M. P

OLLARD s.n., TEX; T. T. ROSS & A. ROSS 5989,

TEX; R

OSS et al. 4946, TEX; D. SEIGIER et al. DS-

2200, TEX; R.

F. THORNE 32857, TEX; WALLACE &

THOMPSON 111, TEX.

Rhus standleyi F.A.B

ARKLEY: C. ANDERSON 5318*,

DUKE; B

REEDLOVE & B. BARTHOLOMEW 60721,

TEX; P.

GUERRERO 135, IEB; E. GUIZAR NOLAZCO &

A. G. MIRANDA 4799, IEB; J. JIMÉNEZ 1678, IEB; M.

LUCKOW 2538, TEX; F. MEDRANO et al. s. n., ANSM;

L. G. Q

UINTERO 2535, TEX; ROMERO ROJAS 1333*,

IEB; R

ZEDOWSKI 25119, 28068, TEX; RZEDOWSKI

52480, IEB; SALINAS D. s.n.*, IEB; STONE 2785*,

DUKE; P. T

ENORIO 4918, IEB; A. VENTURA 3379,

IEB; S.

ZAMUDIO 8378*, IEB; F. ZAVALA 904, ANSM.

Sect. Styphonia subsect. Composita

Rhus andrieuxii E

NGL.: CALZADA 21794*, IBUG;

ARRANZA et al. 1802, ANSM; M. CHÁZARO et al.

6090*, 7065*, IEB; M. N

EGRETE 7065*, IEB;

E. R

ODRÍGUEZ & J. A. VILLAREAL 1751, ANSM;

P. T

ENORIO 5137, IEB; J. VALDÉS s.n., ANSM;

A. VILLAREAL et al. 2705, ANSM.

Rhus nelsonii F.A.B

ARKLEY: J. CALÓNICO 6548*,

7653*, IEB.

Rhus oaxacana L

OES.: S. ACOSTA 947, IEB; M. CHÁ-

ZARO et al. 6801, IEB; T. B. CROAT 46237*, DUKE;

FLORES 1168*, DUKE, IEB; R. ROBLES 84, IEB.

Rhus pachyrrhachis H

EMSL.: M. A. CARRANZA 2727,

ANSM, IEB; M.

A. CARRANZA et al. 2786, ANSM;

INTON et al. 17473, 23602*, 24572, 25096, ANSM,

IEB; H

INTON et al. 22214, IEB; F. MEDRANO et al.

17300, ANSM; A.

MORA 913*, IEB; R. MORAN

10021*, US; RZEDOWSKI 1932, ANSM; RZEDOWSKI

52479*, 54479, IEB; J. A. VILLAREAL & M. CARRANZA

536, ANSM; J.

A. VILLAREAL et al. 5154, ANSM;

ZAMUDIO et al. 11601, IEB.

Rhus schiedeana S

CHLTDL.: BREEDLOVE 26174*,

46237*, DUKE; E. C

ARRANZA 786, 820, 1933, IEB;

R. F

ERNÁNDEZ 3101, 3112, IEB; E. GONZÁLEZ 59*,

IEB; C.

GUZMÁN 64, 114*, IEB; H. RUBIO 320, 1140,

1862, IEB; R

ZEDOWSKI 42980, 43997, 51854, IEB;

B. S

ERVIN 186, 651, IEB; SHILOM TOM 1844*,

DUKE; E. V

ENTURA 6493*, IEB; E. VENTURA &

E. LÓPEZ 9121, ANSM; S. ZAMUDIO et al. 10480,

IEB.

Rhus virens L

INDH. ex A.GRAY: M. A. CARRANZA

C-3643, ANSM; M. A. C

ARRANZA et al. C-682,

C-865, C-2279, 2126, ANSM; J. A. E

NCINA 836*,

ANSM; D.

FLYR 1149*, DUKE; HINTON et al. 24984,

25707, ANSM; C.

L. LUNDELL 12477*, US; J. MAR-

ROQUÍN

1388, ANSM; RZEDOWSKI 50139*, IEB;

P. T

ENORIO 2309, 2357, ANSM.; J. A VILLAREAL

3545, 16948*, ANSM; J. A. V

ILLAREAL et al. 7029,

7313, ANSM; D. B. W

ARD 5786*, DUKE; S. ZAMU-

DIO

2764, 3027, IEB.

Sect. Styphonia subsect. Intermedia

Rhus chondroloma S

TANDL.: F. MCCARTEN 2976*,

US; L.

RICO et al. 329, ANSM; RZEDOWSKI 33957,

IEB; S

ALINAS D. et al. s.n., ANSM.

Funded by

Consejo Nacional de Ciencia y Tecnología for

a scholarship (169599).

Decoding family-level features for modern and fossil leaves from computer-vision heat maps

Article

Full-text available

Mar 2022
AM J BOT

Premise of the study: Angiosperm leaves present a classic identification problem due to their morphological complexity. Computer-vision algorithms can identify diagnostic regions in images, and heat map outputs illustrate those regions for identification, providing novel insights through visual feedback. We investigate the potential of analyzing leaf heat maps to reveal novel, human-friendly botanical information with applications for extant- and fossil-leaf identification. Methods: We developed a manual scoring system for hotspot locations on published computer-vision heat maps of cleared leaves that showed diagnostic regions for family identification. Heat maps of 3114 cleared leaves of 930 genera in 14 angiosperm families were analyzed. The top-5 and top-1 hotspot regions of highest diagnostic value were scored for 21 leaf locations. The resulting data were viewed using box plots and analyzed using cluster and principal component analyses. We manually identified similar features in fossil leaves to informally demonstrate potential fossil applications. Key results: The method successfully mapped machine strategy using standard botanical language, and distinctive patterns emerged for each family. Hotspots were concentrated on secondary veins (Salicaceae, Myrtaceae, Anacardiaceae), tooth apices (Betulaceae, Rosaceae), and on the little-studied leaf margins of untoothed leaves (Rubiaceae, Annonaceae, Ericaceae). Similar features drove the results from multivariate analyses. The results echo many traditional observations, while also showing that most diagnostic leaf features remain undescribed. Conclusions: Machine-derived heat maps that initially appear to be dominated by noise can be translated into human-interpretable knowledge, highlighting paths forward for botanists and paleobotanists to discover new diagnostic botanical characters. This article is protected by copyright. All rights reserved.

Botanical characteristics, biological, chemical and medicinal properties of Rhus natalensis Bernh. ex. Krauss (Anacardiaceae)

Article

Jan 2021

SPECIAL ISSUE-ROTHWELL CELEBRATION MORPHOLOGICAL FEATURES OF SUMAC LEAVES (RHUS, ANACARDIACEAE), FROM THE LATEST EARLY EOCENE FLORA OF REPUBLIC, WASHINGTON

Preprint

Full-text available

Jun 2019

Editor: Michael T. Dunn Premise of research. Newly identified fossils attributable to Rhus (Anacardiaceae) from the latest early Eo-cene flora of Republic, Washington, are recognized. Included are a revision of Rhus malloryi, three new species of Rhus based upon leaflet and rachis morphology, and a group of Rhus leaves showing variation in leaflet morphology , venation, and margin, in part comparable to similar features seen in hybrid angiosperms today. Together, these fossils demonstrate that Rhus was already undergoing diversification in western North America during the latest early Eocene. Methodology. Compression-impression fossils preserved in a lacustrine shale were uncovered from the rock matrix and photographed with light microscopy. Specimens were compared morphologically with fossil and ex-tant material of related plants, and resulting images were processed minimally with Adobe Photoshop. Pivotal results. Fossil Rhus leaves are diverse in the Eocene and demonstrate morphologies characteristic of hybrid leaves in this genus today. Conclusions. This study demonstrates greater systematic diversity than previously known within the genus Rhus in the Okanogan Highlands flora of Republic, Washington. These leaves also provide additional evidence for possible hybridization and other evolutionary processes at play within the sumacs by the latest early Eocene in western North America.

Putative Celtis Leaves from Eocene Patagonia are Allied with Asian Anacardiaceae

Article

Full-text available

Apr 2024
Ameghiniana

The most common macrofossils in the highly diverse flora from Laguna del Hunco (early Eocene of Chubut, Argentina) are "Celtis" ameghinoi leaves, whose true affinities have remained enigmatic for a century. The species accounts for 14% of all plant fossils in unbiased field counts and bears diverse insect-feeding damage, suggesting its high biomass and paleoecological importance. The leaves have well-preserved architecture but lack cuticles or reproductive attachments. We find that the fossils only superficially resemble Celtis and comparable taxa in Cannabaceae, Ulmaceae, Rhamnaceae, Malvaceae, and many other families. However, the distinctive foliar morphology conforms in detail to Dobinea (Anacardiaceae), a genus with two species of shrubs and large herbs ranging from India's Far East and Tibet to Myanmar and central China, and we propose Dobineaites ameghinoi (E.W. Berry) gen et. comb. nov. for the fossils. This discovery strengthens the extensive biogeographic links between Eocene Patagonia and mainland Asia, provides the first fossil record related to Dobinea, and represents a rare Gondwanan macrofossil occurrence of Anacardiaceae, which was widespread and diversified in the Northern Hemisphere at the time. The diverse leaf architecture of Anacardiaceae includes several patterns usually associated with other taxa, and many other leaf fossils in this family may remain misidentified.

Eurypollinic pollen of the Anacardiaceae differentiates taxa

Article

Full-text available

May 2022

The pollen morphology of 11 Anacardiaceae species from the Mexican State of Veracruz was studied. Pollen grains were acetolyzed and examined under light and scanning electron microscopy to determine whether their morphological characteristics are useful to differentiate taxa in this family. Photomicrographs were obtained with both types of microscopes and used as the basis for describing the pollen. Pollen descriptions included traits such as shape, the type and number of apertures, exine ornamentation, size of the polar and equatorial axes, and diameter in polar view. Most species have isopolar pollen grains, with tricolpate or tricolporate apertures. Only Pistacia mexicana has pentaporate pollen. Pollen grains exhibit a triradial or radial symmetry in polar view; their shape in equatorial view can be prolate-spheroidal, subprolate, or prolate. The size of axes in equatorial view, diameter in polar view, and the exine ornamentation show distinctive characteristics in each species. However, the most common ornamentation types are microreticulate and microstriate. Ten pollen types were identified based on combinations of traits such as the type and number of apertures, shape in equatorial and polar view, and exine ornamentation. The results confirm that the eurypollinic pollen of Anacardiaceae is valuable for differentiating taxa, highlights the importance of studying pollen morphology and contributes to increasing the knowledge about the pollen morphology of this family in Mexico.

Neotropical Anacardiaceae (cashew family)

Article

Full-text available

Apr 2022
Rev Bras Botânica

Anacardiaceae is an ecologically and economically important plant family of about 200 species in 32 genera in the Neotropics. The family is particularly diverse in leaf architecture and fruit morphology, making it a model family to study the evolution of structural diversity as it correlates with lineage diversification. This fruit diversity is the primary reason 11 of the Neotropical genera are monotypic and that so many genera are recognized in the Anacardiaceae. The economic value of the family is driven by the global markets for cashews, mangoes, and pistachios, but there is great potential value in its medicinal properties. At least 10 Neotropical genera cause contact dermatitis, which is a rich area for research in the family. Here presented is a review of the systematics and structural diversity of the family. Particular attention is given to the morphology, economic botany, paleobotany, ecology, and taxonomy of native and naturalized genera. Keys to Neotropical Anacardiaceae subfamilies and genera are provided along with descriptions of native genera.

Phenolic Composition and Biological Properties of Rhus microphylla and Myrtillocactus geometrizans Fruit Extracts

Article

Full-text available

Sep 2021

Plants from arid zones of Mexico are an interesting source of phytochemicals that exhibit a large number of biological properties. In this context, Rhus microphylla (Rm) and Myrtillocactus geometrizans (Mg) fruits have been used as folk remedies and to make traditional foods, respectively; however, studies on their composition and bioactivity are limited. Thus, the objective of this work was to evaluate the yields, phenolic composition, and bioactive properties (scavenging and reducing capacities, antiproliferative, and antifungal) of aqueous and hydroalcohol extracts of Rm and Mg fruits obtained by conventional agitation and ohmic heating (OH). The results showed that the Rm fruit extracts had the highest total phenolic content (TPC) values and the strongest scavenging and reducing capacities compared to those of Mg fruits, being characterized by the presence of gallic acid, while the composition of the Mg extracts varied with respect to the extraction conditions used. Regarding antifungal activity in vitro against two phytopathogenic fungi, Rhizopus stolonifer and Fusarium oxysporum, the hydroalcohol extracts obtained by conventional agitation of both plants (RmH-C and MgH-C) showed the best inhibitory effect, respectively. Interestingly, none of the extracts under study presented cytotoxicity against the noncancerous ARPE-19 cell line, while three extracts of Rm fruit exhibited a moderate antiproliferative activity against HeLa (cancerous) cell line. These findings reveal for the first time the potential of Rm and Mg fruits as a new source of bioactive compounds

Foliar Micromorphology and Anatomy of Five Mediterranean Enclaves in Artvin (Turkey)

Article

Sep 2020

Aim of study: We aimed to investigate leaf micromorphology including venation types, and petiole and leaf blade anatomical characteristics of five woody/scrubs Mediterranean enclaves (Cotinus coggygria Scop., Rhus coriaria L., Arbutus andrachne L., Punica granatum L. and Jasminum fruticans L.) in this study. Area of study: Artvin Province has three distinct climate types. The species studied were collected from natural habitats in Artvin, where Mediterranean climate type occurs. Material and methods: Leaves of five species were evaluated micromorphologically and anatomically by using stereomicroscopy, light microscopy and scanning electron microscopy. Main results: Two species have imparipinnately compound leaves, while three have simple ones. Four venation types were determined in the species. C. coggygria has channeled anticlinal walls of adaxial epidermal cells and A. andrachne has striate cuticular ornamentation in the abaxial surfaces. Differently from others, R. coriaria and J. fruticans have glandular trichomes, and P. granatum has bicollateral vascular bundle. Secretory canals and druses crystals were detected in some investigated species. Most of the species have hypostomatic leaf type, but J. fruticans has amphistomatic one. The highest stomata number and indices per mm2 were observed in P. granatum, while the lowest values were found in J. fruticans. Research highlights: Among the species examined, Punica granatum with the highest stomatal number and indices per mm2, narrowed and deciduous leaf with epicuticular wax composition has probably distinctive adaptive strategies to water deficiency and xerophytic habitats

Plastid genomes of the North American Rhus integrifolia-ovata complex and phylogenomic implications of inverted repeat structural evolution in Rhus L

Article

Full-text available

Jun 2020

Craig F Barrett

Plastid genomes (plastomes) represent rich sources of information for phylogenomics, from higher-level studies to below the species level. The genus Rhus (sumac) has received a significant amount of study from phylogenetic and biogeographic perspectives, but genomic studies in this genus are lacking. Rhus integrifolia and R. ovata are two shrubby species of high ecological importance in the southwestern USA and Mexico, where they occupy coastal scrub and chaparral habitats. They hybridize frequently, representing a fascinating system in which to investigate the opposing effects of hybridization and divergent selection, yet are poorly characterized from a genomic perspective. In this study, complete plastid genomes were sequenced for one accession of R. integrifolia and one each of R. ovata from California and Arizona. Sequence variation among these three accessions was characterized, and PCR primers potentially useful in phylogeographic studies were designed. Phylogenomic analyses were conducted based on a robustly supported phylogenetic framework based on 52 complete plastomes across the order Sapindales. Repeat content, rather than the size of the inverted repeat, had a stronger relative association with total plastome length across Sapindales when analyzed with phylogenetic least squares regression. Variation at the inverted repeat boundary within Rhus was striking, resulting in major shifts and independent gene losses. Specifically, rps19 was lost independently in the R. integrifolia-ovata complex and in R. chinensis , with a further loss of rps22 and a major contraction of the inverted repeat in two accessions of the latter. Rhus represents a promising novel system to study plastome structural variation of photosynthetic angiosperms at and below the species level.

Morphological Features of Sumac Leaves (Rhus, Anacardiaceae), from the Latest Early Eocene Flora of Republic, Washington

Article

Jul 2019

Premise of research. Newly identified fossils attributable to Rhus (Anacardiaceae) from the latest early Eocene flora of Republic, Washington, are recognized. Included are a revision of Rhus malloryi, three new species of Rhus based upon leaflet and rachis morphology, and a group of Rhus leaves showing variation in leaflet morphology, venation, and margin, in part comparable to similar features seen in hybrid angiosperms today. Together, these fossils demonstrate that Rhus was already undergoing diversification in western North America during the latest early Eocene. Methodology. Compression-impression fossils preserved in a lacustrine shale were uncovered from the rock matrix and photographed with light microscopy. Specimens were compared morphologically with fossil and extant material of related plants, and resulting images were processed minimally with Adobe Photoshop. Pivotal results. Fossil Rhus leaves are diverse in the Eocene and demonstrate morphologies characteristic of hybrid leaves in this genus today. Conclusions. This study demonstrates greater systematic diversity than previously known within the genus Rhus in the Okanogan Highlands flora of Republic, Washington. These leaves also provide additional evidence for possible hybridization and other evolutionary processes at play within the sumacs by the latest early Eocene in western North America.

THE TERMINAL IDIOBLASTS IN MAGNOLIACEOUS LEAVES

Article

Nov 1964

Shirley C. Tucker

The idioblasts terminating the foliar veinlets were studied in 152 species of the following magnoliaccous genera: Alcimandra, Aromadendron, Elmerrillia, Kmeria, Liriodendron, Magnolia, Manglietia, Michelia, Paramichelia, and Talauma. In all genera, except Liriodendron, some of the veinlets in mature leaves terminate in enlarged, nonliving cells called tracheoidal elements. Only one wall-facet (rarely 2) in such elements is differentially thickened; this wall lies adjacent to a conventional tracheary element. Ultimate cells of other veinlets in the Magnoliaceae differentiate as thick-walled sclereids, conventional tracheids, clavate tracheids, reticulate-walled dilated tracheids, or secretory cells. The terminal elements differentiate relatively late during leaf enlargement. In the Magnoliaceae, foliar structure is frequently characteristic at the generic level, and in some cases at the species level.

HEARTWOOD FLAVONOIDS AND THE INFRAGENERIC RELATIONSHIPS OF RHUS (ANACARDIACEAE)

Article

May 1979

David A. Young

Heartwood flavonoids of 23 taxa of Rhus L. were surveyed in order to assess infrageneric relationships and classification. Fourteen flavonoids and two coumarins were detected in the heartwood extracts. All taxa were characterized by a flavonoid complement consisting of eight 5-deoxyflavonoids involving several aglycone classes (e.g., flavonols, flavones, aurones, chalcones and dihydroflavonols) and the aurone rengasin. None of the 5-hydroxyl analogs of the 5-deoxyflavonoids were detected in the heartwood extracts. Infraspecific flavonoid patterns were uniform in different populations, although the presence of 3′,4′-dihydroxyflavone 4′-O-β-glucoside varied in some taxa. Taxa of Rhus subgenus Rhus consistently differed from all taxa of Rhus subgenus Lobadium in lacking glycosides of fisetin, butein and 3′,4′-dihydroxyflavone. The major evolutionary trend in the heartwood flavonoids of Rhus appears to be accumulation of simple mono- or diglucosides. Data from heartwood flavonoids suggest that Rhus be treated as consisting of two subgenera (Rhus and Lobadium) and that subgenus Lobadium be divided into three sections.

CLASSIFICATION OF THE ARCHITECTURE OF DICOTYLEDONOUS LEAVES

Article

Jan 1973

Leo J. Hickey

A classification of the architectural features of dicot leaves—i.e., the placement and form of those elements constituting the outward expression of leaf structure, including shape, marginal configuration, venation, and gland position—has been developed as the result of an extensive survey of both living and fossil leaves. This system partially incorporates modifications of two earlier classifications: that of Turrill for leaf shape and that of Von Ettingshausen for venation pattern. After categorization of such features as shape of the whole leaf and of the apex and base, leaves are separated into a number of classes depending on the course of their principal venation. Identification of order of venation, which is fundamental to the application of the classification, is determined by size of a vein at its point of origin and to a lesser extent by its behavior in relation to that of other orders. The classification concludes by describing features of the areoles, i.e., the smallest areas of leaf tissue surrounded by veins which form a contiguous field over most of the leaf. Because most taxa of dicots possess consistent patterns of leaf architecture, this rigorous method of describing the features of leaves is of immediate usefulness in both modern and fossil taxonomic studies. In addition, as a result of this method, it is anticipated that leaves will play an increasingly important part in phylogenetic and ecological studies.

Comparative Wood Anatomy of Malosma and Related Genera (Anacardiaceae)

Article

Jan 1974

David Young

Stem and Leaf Anatomy of the Alseuosmiaceae

Article

Jan 1989

William C. Dickison

Methods for Comparative Wood Anatomy Studies

Chapter

Jan 1988

Sherwin Carlquist

The sliding microtome (sledge) has been the standard instrument for preparation of wood sections, and its use seems likely to continue indefinitely. The sliding microtome is useful because most woods have degrees of hardness suitable for this instrument. Excessively hard woods can be softened by the use of ethylene diamine (Kukachka 1977). The use of hydrofluoric acid for this purpose is disadvantageous because it requires more time than ethylene diamine, and is dangerously corrosive. Ethylene diamine is not without risks, and should be used with care because of its vapors and its strong alkalinity. However, ethylene diamine, used in various dilutions and with the aid of heat (as in paraffin oven) or at room temperature can soften more effectively than hydrofluoric acid in shorter periods of time. As with hydrofluoric acid, treatment with ethylene diamine can result in swelling of certain cell walls, especially if treatment is excessive.

Leaf anatomy of Harpullia, Majidea and Conchopetalum (Sapindaceae)

Article

Jan 1995

J.R. Buijsen

Wood anatomy and pollen morphology of Rhus and allied genera

Article

C. Heimsch

Anatomical features of the leaves in the Dichrostachys group (Leguminosae: Mimosoideae) and their utility for phylogenetic studies

Article

Jan 2002

M. Lucknow

Leaflet anatomy of 30 species in the genera Alantsilodendron, Calliandropsis, Dichrostachys, and Gagnebina, was studied using hand-sections, leaf clearings, and scanning electron microscopy. Variation was found in the distribution of stomata, venation patterns, and especially sclerification associated with the vascular tissue. Terminal idioblasts are common and diverse, with enlarged tracheids, tracheoidal elements, reticulate and pitted tracheids, and sclereids associated with the terminal veinlets. In addition, sclerification of bundle sheath cells was found in two of the genera, and non-terminal sclereids of unknown origin are reported in yet a third genus. Although many characters of leaf anatomy are strongly correlated with ecological factors, an evaluation of such characters in the context of a preliminary phylogeny indicates that they are useful in phylogeny reconstruction. The major limitation in the use of anatomical characters of leaves in phylogenetics seems to be the difficulty in defining discrete character states and not ecological plasticity.

The Suitability of Molecular and Morphological Evidence in Reconstructing Plant Phylogeny

Chapter

Jan 1992

Renewed interest in phylogenies over the last few decades coincides with a growing sense that it will actually be possible to obtain an accurate picture of evolutionary history. Indeed, the prospects of retrieving phylogeny now seem better than ever, owing to basic theoretical advance (due mainly to Hennig, 1966), the availability of computer programs that can handle large data sets, and the accessibility of new sources of evidence, especially molecular characters.

Leaf architecture of Rhus s.str. (Anacardiaceae)

Abstract and Figures

Recommended publications

The Effect of Premature Birth on The Primary Dentition

Hemostatic agents for pulpotomy treatment in primary teeth

Vertical alveolar growth in subjects with infraoccluded mandibular deciduous molars

Dental trauma in the primary dentition