Four New Vining Species of Solanum (Dulcamaroid Clade) from Montane Habitats in Tropical America

Abstract

Solanum (Solanaceae), with approximately 1500 species, is one of the largest genera of flowering plants, and has a centre of diversity in the New World tropics. The genus is divided into 13 major clades, of which two, the Dulcamaroid clade and the "African Non-Spiny" clade, exhibit vine morphology with twining petioles. I am currently preparing a worldwide monograph of these two groups, comprising some 70 species.
I formally describe here four new species of Solanum from montane Mexico and South America all belonging to the Dulcamaroid clade (including the traditionally recognised section Jasminosolanum Bitter). Descriptions, discussions of closely related species and preliminary conservation assessments are provided for all species; all species are illustrated. This paper is also a test case for the electronic publication of new names in flowering plants.
These new species are all relatively rare, but not currently of conservation concern. Solanum aspersum sp. nov. is distributed in Colombia and Ecuador, S. luculentum sp. nov. in Colombia and Venezuela, S. sanchez-vegae sp. nov. is endemic to northern Peru and S. sousae sp. nov. to southern Mexico. Solanum luculentum has the morphology of a dioecious species; this is the first report of this breeding system in the Dulcamaroid clade.

Full text

Four New Vining Species of
Solanum
(Dulcamaroid
Clade) from Montane Habitats in Tropical America
Sandra Knapp*
Department of Botany, The Natural History Museum, London, United Kingdom
Abstract
Background:
Solanum (Solanaceae), with approximately 1500 species, is one of the largest genera of flowering plants, and
has a centre of diversity in the New World tropics. The genus is divided into 13 major clades, of which two, the Dulcamaroid
clade and the ‘‘African Non-Spiny’’ clade, exhibit vine morphology with twining petioles. I am currently preparing a
worldwide monograph of these two groups, comprising some 70 species.
Methods:
I formally describe here four new species of Solanum from montane Mexico and South America all belonging to
the Dulcamaroid clade (including the traditionally recognised section Jasminosolanum Bitter). Descriptions, discussions of
closely related species and preliminary conservation assessments are provided for all species; all species are illustrated. This
paper is also a test case for the electronic publication of new names in flowering plants.
Conclusions:
These new species are all relatively rare, but not currently of conservation concern. Solanum aspersum sp. nov.
is distributed in Colombia and Ecuador, S. luculentum sp. nov. in Colombia and Venezuela, S. sanchez-vegae sp. nov. is
endemic to northern Peru and S. sousae sp. nov. to southern Mexico. Solanum luculentum has the morphology of a
dioecious species; this is the first report of this breeding system in the Dulcamaroid clade.
Citation: Knapp S (2010) Four New Vining Species of Solanum (Dulcamaroid Clade) from Montane Habitats in Tropical America. PLoS ONE 5(5): e10502.
doi:10.1371/journal.pone.0010502
Editor: Samuel T. Turvey, Zoological Society of London, United Kingdom
Received November 3, 2009; Accepted February 16, 2010; Published May 5, 2010
Copyright: ß2010 Sandra Knapp. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: Financial support for this work came from the National Science Foundation Planetary Biodiversity Inventory (award DEB-0316614, ‘‘PBI Solanum–A
Worldwide Treatment’’) (http://www.nsf.gov). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the
manuscript.
Competing Interests: The author has declared that no competing interests exist.
* E-mail: s.knapp@nhm.ac.uk
Introduction
Solanum is one of the ten most species-rich genera of flowering
plants [1]. With approximately 1500 species (J. Bennett & S.
Knapp, unpubl.) occurring on all temperate and tropical
continents, the genus occupies an incredibly wide range of habitats
and habits, paralleling that of the family. The history of Solanum
classification has been reviewed previously [2], but the last time
the genus was monographed in its entirety was in De Candolle’s
Prodromus [3]. Current work by participants of the ‘‘PBI Solanum’’
project (see www.nhm.ac.uk/solanaceaesource) will result in a
modern monographic treatment of the entire genus available on-
line. Solanum can be divided into 13 well-supported monophyletic
clades [4,5], the largest of which is the group commonly known as
the spiny solanums (the Leptostemonum clade). The largest non-
spiny solanum clade is the Morelloid/Dulcamaroid clade,
comprising all the herbaceous species previously placed in section
Solanum [6] and allied groups, and the vining species placed in
sections Jasminosolanum,Dulcamara., Lysiphellos and Andropedas plus a
variety of other taxa [4]. All these species (plus other species
previously recognised as section Parasolanum Bitter, e.g. S.
corymbosum Jacq.) have previously been combined into a single
section Dulcamara (Moench) Dumort. [6]; included in this
circumscription the African S. terminale Forssk. and its relatives,
which in molecular analyses form a distinct clade called the
‘‘African Non-Spiny’’ clade [4].
The monophyletic group here referred to as the Dulcamaroid
clade appears to be sister to the Morelloids [5], and includes a
wide variety of groups previously thought to be unrelated. The
woody members of the S. nitidum species group [7] belong here, as
do several shrubby species (e.g., S. aligerum,S. pubigerum) previously
thought to allied to the members of section Geminata [2,8]. Most
members of the clade, however, are woody vines, often reaching
the canopy and thus not often collected. Members of the clade
share a peculiar inflorescence morphology in which the pedicel is
inserted into a small cup or sleeve on the inflorescence axis, so that
when abscission occurs a distinct cup is left behind [7]. The vining
members of the group climb by means of twining petioles; petioles
on older leaves are often very thick and woody.
Members of the Dulcamaroid group occur in both the Old and
New Worlds, with the Old World taxa largely boreal (e.g., S.
dulcamara L. and relatives) and those of the New World mostly
tropical, with high species diversity in southeastern Brazil [9].
Montane regions are also areas of high species diversity in the
group. In the course of preparing a monographic treatment of the
Dulcamaroid group a number of new montane taxa were
encountered; these are described here in order that the names
may used in the on-line treatment and in floristic works. This
contribution is the first to publish new plant names in a purely
electronic journal, and thus serves as a test case for changes being
developed for the International Code of Botanical Nomenclature
[10]. Discussion of previous changes to the ICBN to facilitate
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electronic publication can be found elsewhere [11,12,13]. Digital
images of all type specimens and complete specimen label
information can be found on Solanaceae Source (www.nhm.ac.
uk/solanaceaesource).
Results and Discussion
Taxonomic treatment
Solanum aspersum S.Knapp, sp. nov. [urn:lsid:ipni.org:
names:77103633-1] Type: Colombia. Putumayo: vertiente orien-
tal de la Cordillera, entre Sachamates y San Francisco de
Sibundoy, 1600–1750 m, 30 Dec 1940, J. Cuatrecasas 11471
(holotype, COL; isotypes, F [F-1335119], US [US-1799731]).
Figure 1.
Species Solano aureo Dunal similis, sed foliis bullatis, trichoma-
tibus uniseratis simplices, gemmis elongatis, corollis profunde
stellatis, differt.
Woody vine, of unspecified length or height; stems densely and
evenly pubescent with antrorsely curved simple uniseriate
trichomes 0.5–1.5 mm long, these few-celled with a large basal
cell, arising from expanded bases and eventually deciduous; new
growth densely pubescent with simple uniseriate trichomes to
1.5 mm, these pale straw-colored in herbarium specimens; bark of
older stems greenish brown, minutely tuberculate from the bases
of the deciduous trichomes. Sympodial units plurifoliate. Leaves
simple, (12)3.5–96(0.62)1.5–4.6 cm, ovate to narrowly ovate,
widest in the basal third, membranous or chartaceous, strongly
discolorous, the upper surfaces evenly pubescent on veins and
lamina, the trichomes to 2 mm long, simple, uniseriate, arising
from expanded bases giving the lamina surface a tuberculate
appearance, the lower surfaces densely and evenly pubescent with
simple uniseriate trichomes to 2 mm, these 2-3-celled with the
basal cell largest, denser on the veins; primary veins 7–9 pairs,
impressed above in herbarium specimens; base truncate or
shallowly cordate; margins entire, not revolute; apex acute to
acuminate; petioles 0.7–2 cm, densely pubescent with simple
trichomes like those of the stems and leaves. Inflorescences
terminal on leafy short shoots, 3–15 cm long, globose to ellipsoid
in outline, branching many times, with 2 principal basal branches,
with 12–60 flowers, densely pubescent with simple trichomes;
peduncle 0.5–3 cm, the branching very near the junction with the
stem; pedicels 0.5–0.8 cm, ,0.5 mm in diameter at the base and
apex, pubescent with 1-2-celled simple trichomes to 1.5 mm long,
spreading at anthesis, articulated near the base from a small sleeve,
leaving a small peg on the axis; pedicel scars irregularly spaced 1–
10 mm apart, the inflorescence rachis bending at almost right
angles at articulation points. Buds narrowly ellipsoid, the corolla
strongly exserted from the calyx tube. Flowers all perfect, 5-
merous; calyx tube ca. 2 mm, conical, the lobes 0.5–1 mm, deltate
to broadly deltate, pubescent with simple trichomes, these sparser
than on the rest of the inflorescence; corolla 1.2–1.7 cm in
diameter, white, pink or ‘‘pale blue’’ (violet?), narrowly stellate,
lobed nearly to the base, the lobes 6–761.5–2 mm, reflexed at
anthesis, glabrous adaxially, densely pubescent abaxially with
Figure 1.
Solanum aspersum
.A) portion of stem, with details of trichomes, B) young bud, C) open flower, D) fruiting inflorescence, E) young fruit.
A–C drawn from MacDougal et al. 4251, D–E from Zak 1857A.
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weak simple papillate trichomes to 0.5 mm long, these denser on
tips and margins; filament tube ,0.5 mm, the free portion of the
filaments ca. 0.5 mm, glabrous; anthers 4–4.5 x ca. 1 mm, yellow,
ellipsoid, poricidal at the tips, the pores lengthening to slits with
age; ovary glabrous; style 5–6 mm long, pubescent with weak
simple trichomes to 0.5 mm, more densely pubescent in the basal
half; stigma capitate-truncate, the surface minutely papillose. Fruit
a globose berry, ca. 1.3 cm in diameter (immature?), green or
yellowish green, the pericarp thin and shiny, glabrous; fruiting
pedicels 0.9–1 cm, 1–1.5 mm in diameter at the base, woody and
spreading. Seeds not seen from mature berries, apparently 10+per
berry and flattened reniform.
Distribution. Solanum aspersum occurs in widely separated and
isolated populations along the Andes from central Ecuador into
Colombia in both the Cordillera Occidental and the Cordillera
Central, from 1600 to 2500 m.
Etymology. The specific epithet refers to the few and
scattered collections of this species (aspersus = scattered) along
the Andes from Ecuador to Colombia that have been subsumed in
the more common Solanum aureum.
Preliminary conservation status. Although known from
very few herbarium specimens, S. aspersum has a wide distribution,
and is possibly more common in its total range than currently
known.
Additional specimens examined. COLOMBIA.Antioquia:
Mun. Urrao, between Urrao and Caicedo, 21 km E of Urrao,
near high point on road, 6u249N, 76u029W, 27 Feb 1989,
MacDougal et al. 4251 (MO). Cundinamarca: 17 Feb 1950, von
Sneidern 5825 (S). ECUADOR.Napo: Parroquia Cosanga, 6 kms de
la carretera Cosanga-El Aliso, 23 Aug 1990, Jaramillo et al. 12110
(MO). Canton Quijos, Rı
´o Aliso, 8 km al suroeste de Cosanga,
0u379S, 77u569W, 15 Nov 1998, Vargas et al. 3043 (MO).
Pichincha: km 59 de la carretera antigua Quito-Santo
Domingo de los Colorados, a 3.5 km al NE de la carretera, 28
Mar 1987, Zak 1857A (F, MO).
The few specimens of Solanum aspersum have usually been
annotated as the more common and widely distributed S. aureum
Dunal, also from Andean Ecuador. Solanum aspersum differs from
that species in its simple uniseriate, rather than congested-
dendritic pubescence (Fig 1A), and in the elongate buds that open
to deeply stellate flowers (Fig. 1B, C). Specimens of S. aureum from
Azuay province in Ecuador have similarly shiny adaxial leaf
surfaces to S. aspersum, but always have the characteristic golden
dendritic pubescence of that species rather than the simple
pubescence of S. aspersum. The leaves of S. aspersum are usually
more cordate than those of S. aureum, but some populations of S.
aureum approach S. aspersum in overall leaf morphology at first
glance. Solanum aspersum has a very scattered distribution all along
the Andes from northern Colombia to central Ecuador and is
likely to be found in more of the intervening parts of the
cordilleras, but it is apparently rare and easily overlooked.
Solanum luculentum C.V.Morton ex S.Knapp, sp. nov.
[urn:lsid:ipni.org:names:77103634-1] Type: Colombia. Antioquia:
Mpio. Sonso´n, Vereda Manzanares, Finca La Montan˜ita, Cerro
de la Vieja, pa´ ramo de Sonso´n, 2600–3100 m, 11 Jan 1995, J.
Betancur & S.P. Churchill 5912 (holotype, COL [COL000057871];
isotype, HUA).
Figure 2.
Species Solano dichroandro Dunal similis, sed corticibus exfoliatis,
foliis glabris nitidis, floribus heterostylibus (unisexualibus?), differt.
Woody vines or lianas, occasionally apparently epiphytic, to
6 m; stems glabrous and shiny; new growth almost completely
glabrous, with extremely sparse pubescence of minute, golden
multiseriate trichomes ,0.5 mm long; bark of older stems pale tan
and markedly exfoliating (‘‘shreddy’’ fide Nee & Callejas 32546).
Sympodial units plurifoliate. Leaves simple, 2–1160.l7–5 cm,
elliptic to narrowly elliptic, coriaceous, the upper surfaces glabrous
and shiny, the veins not apparent, the lower surfaces glabrous, the
veins yellowish cream; primary veins 5–7 pairs, prominent below,
obscure above; base cuneate to acute to truncate and occasionally
slightly cordate; margins entire, strongly revolute in both dry and
live (fide Steyermark et al. 100777) plants; apex acute or occasionally
long acuminate; petioles 0.7–3 cm, glabrous or with a few
scattered glandular papillae, wrinkly when dry. Inflorescences
terminal, 3–11 cm long, more or less ellipsoid in outline, many
times branched, with 20–50 flowers, glabrous; peduncle 0.5–2 cm
long, branching from very near the base; pedicels 1.2–1.5 cm,
slender, ca. 0.5 mm in diameter at the base, ca. 1 mm in diameter
at the apex, glabrous, apparently somewhat erect at anthesis,
articulated just above the base, leaving a prominent swelling on
the axis; pedicel scars irregular spaced 2–10 mm apart. Buds
globose, becoming ellipsoid to turbinate, the corolla strongly
exserted from the calyx tube early in expansion. Flowers
heterstylous, 5-merous, the plants probably dioecious, long-styled
and short-styled flowers on different plants but of similar overall
morphology; calyx tube 1.5–2 mm, conical, the lobes 0.5–1 mm,
broadly deltate, glabrous with the tips minutely papillate; corolla
1.5–1.7 cm in diameter, white or occasionally tinged with
lavender, stellate, lobed 2/3 to 3/4 of the way to the base, the
lobes 6–763–4 mm, planar at anthesis, densely papillose on tips
and margins with golden simple trichomes, these occasionally
extending along the midvein of the abaxial surface; filament tube
minute, the free portion of the filaments ca. 1 mm, glabrous;
anthers of long-styled flowers ca. 461 mm, occasionally slightly
shrivelled, those of short-styled flowers ca. 561.5 mm, yellow,
ellipsoid to pointed ellipsoid, poridical at the tips, the pores with
thickened margins and lengthening to slits with age; ovary
glabrous, vestigial in short-styled flowers; style in long-styled
flowers 5–6 mm, exserted beyond the anthers, glabrous, in short-
styled flowers 2.5–3 mm, included in the anther tube, glabrous;
stigma clavate, the surface densely papillose in long-styled flowers.
Fruit a globose berry, to 2 cm in diameter, green (immature?), the
pericarp quite thin but not markedly shiny; fruiting pedicels 1.5–
2 cm, ca. 2–3 mm in diameter at the apex, woody and nodding.
Seeds 10–12 per berry, 6–864–6 mm, flattened reniform, pale
tan, the surfaces minutely pitted, the testal cells rectangular at the
margins, deeply sinuate with rib-like thickenings on the lateral
walls in the seed center.
Distribution. Solanum luculentum occurs in the Andes of
Colombia (Depts. Antioquia, Cundinamarca and Narin˜o) and
Venezuela (from the Colombian border to the Federal District
around Caracas) in cloud forests from 1500 to 3200 m.
Etymology. The epithet, taken from annotations by the
solanologist Conrad V. Morton on sheets in US, refers to the
extremely shiny upper surfaces of the leaves (luculentus = full of
light, splendid).
Preliminary conservation status. Solanum luculentum is
widely distributed across northern South America and appears
to be relatively common where it does occur, but the extent of
damage to its cloud forest habitat needs assessment. It should be
considered not threatened at present.
Additional specimens examined. COLOMBIA.Antioquia:
Mun. Caldas, Vereda La Corrala, al lado del camino al la cascada,
21 Sep 1987, Albert de Escobar et al. 7939 (MO); sin. loc., 28 Dec
1930, Archer 1153 (US,) 1 Jan 1931, Archer 1227 (US); en los
alrededores [de Medellı
´n], 21 Aug 1948, Barkley & Johnson 264
(US); near Medellı
´n, Bros. Daniel & Arse`nio 3486 (US); La Ceja, 21
Jul 1944, Bro. Daniel 3281 (US); midway between Medellı
´n and Rı
´o
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Negro, 6u059N, 75u259W, 8 Jul 1986, Nee & Callejas 32456 (US);
Mun. Salgar, km 15 of road Salgar-Hacienda El Dauro (Dpto.
Choco´), 5u599N, 76u069W, 14 Mar 1987, Zarucchi & Echeverri 4753
(K); Mun. Jardı
´n, km 20 of road Jardı
´n-Riosucio (Dept. Caldas),
ca. 15 km SSE of Jardı
´n, 5u319N, 75u489W, 29 Oct 1988, Zarucchi
et al. 6928 (K). Boyaca
´: Cordillera Oriental, near Laguna Seca in
valley of Rı
´o de los Pajaros, 26 Aug 1957, Grubb et al. 737a (K).
Cundinamarca: carretera a Fusagasuga´, 9 May 1949, Garcı
´a-
Barriga 13335 (US). Santander: in vicinity [of Santander], 21 Dec
1926, Killip & Smith 15952 (US). VENEZUELA.Aragua: sin. loc.,
1856, Fendler 2099 (GOET, K, MO); 4 km SW by air, on road to
Capachal 2 km east from road between Colonia Tovar and La
Victoria, 10u229N, 67u199W, 7 Apr 1982, Liesner & Medina 13496
(MO). Distrito Federal: Dept. Libertador, a lo largo del camino
Costa de Maya, noroeste de la Colonia Tovar, 3–5 kms desde la
carretera principal La Victoria-Colonia Tovar, 10u259N,
67u209050W, 9 Dec 1982, Steyermark et al. 127855 (MO).
Tachira: cabeceras del Rı
´o Quinimari, entre el pie´ del pen˜ asco
de la Pen˜a de Pata de Judio (debajo del pa´ ramo del Judio), y el pie´
del salto de Chorrejo´n de la Mota de la Pen˜ a de Ventana, arriba
de Las Copas, 18–20 kms al sur de San Vicente de la Revancha,
32–35 kms al sur de Alquitrana, suroeste de Santa Ana, 12 Jan
1968, Steyermark et al. 100777 (US).
Solanum luculentum was identified as a new species by the
Solanaceae specialist ConradV. Morton in the 1940s on
herbarium annotation slips on specimens in US (Archer 1153,
1227), but the very appropriate name was never published. I have
decided to use it here, as it perfectly describes the distinguishing
characteristic of this species, its coriaceous, lustrous and shining
leaves (Fig. 2B). Solanum luculentum has long been confused with S.
Figure 2.
Solanum luculentum
.A) portion of stem with flowering inflorescence, B) detail of stem with peeling bark, C) buds, D) open long-styled
flower with anthers removed, E) long-styled flower cross-section, F) anthers, G) short-styled flower cross-section, H) fruiting inflorescence from
putatively pistillate individual. A–B drawn from Nee & Callejas 32546, C–F from Steyermark et al. 127855, G from Steyermark & Dunsterville 100777,H
from Killip & Smith 15952.
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dichroandrum Dunal, another vining species from northern South
America, but differs from that in its completely glabrous leaves and
inflorescences, revolute leaf margins and heterostylous flowers.
Specimens of S. luculentum, to my knowledge, either bear short-
styled flowers and no fruits or long-styled flowers and fruits (see
Fig. 2D, E, F); this is indicative of a dioecious species of Solanum,
one of very few outside the Leptostemonum clade [14], and the
first record for this breeding system in the Dulcamaroid clade.
Field confirmation of the breeding system of S. luculentum will be
interesting; pollen of this species has not yet been examined to
ascertain if it is inaperturate, as is pollen of other dioecious
solanums [14].
Solanum sanchez-vegae S.Knapp, sp. nov. [urn:lsid:
ipni.org:names:77103635-1] Type: Peru. Amazonas: Prov. Cha-
chapoyas, W side of Cerros Calla-Calla, 45 km above Balsas, mid-
way on road to Leimebamba, 3100 m, 19 Jun 1964, P.C. Hutchison
& J.K. Wright 5738 (holotype, USM; isotypes, F [F-163831], K
[K000545365], P [P00549320], US [US-246605], USM).
Figure 3, 4.
Species Solano aureo Dunal similis, sed foliis laxe pubescentibus,
floribus maioribus, stylis glabris, seminibus paucis, differt.
Woody vine or lax shrub, to 6 m; stems glabrous to sparsely
pubescent with tangled loose dendritic trichomes 1–1.5 mm, these
multi-celled and few branched; new growth pubescent with
tangled dendritic trichomes 1–1.5 mm, occasionally almost
completely glabrous; bark of older stems reddish brown,
glabrescent. Sympodial units plurifoliate. Leaves simple,
(2.52)5–126(1.32)2.5–5 cm, narrowly elliptic, fleshy to charta-
ceous, the upper surfaces glabrous, the lower surfaces with loose
dendritic trichomes to 1 mm long along the veins and occasionally
extending to the lamina; primary veins 11–14, with a prominent
intramarginal vein looping 1/3 of the way in from the margin, all
veins impressed above; base acute to cuneate; margins entire,
usually revolute; apex acute; petioles 1–3.5 cm, stout, glabrous to
sparsely pubescent, often drying dark in herbarium specimens.
Inflorescences terminal, to 15 cm long and very broad, globose in
outline, branched many times from very near the base, with 50–
100 flowers, glabrous to sparsely pubescent with loose dendritic
trichomes; peduncle to 1 cm, the inflorescence branching very
near the junction with the stem; pedicels 1.2–1.5 cm, slender, 0.5–
1 mm in diameter at the base, 1–1.2 mm in diameter at the apex,
spreading at anthesis, glabrous to very sparsely pubescent,
Figure 3.
Solanum sanchez-vegae
.A) portion of stem, B) petiole articulation, C) buds, D) open flower, E) flower cross-section showing stigma detail,
F) anthers, G) fruit. A–F drawn from Smith & Sanchez-Vega 7524, G from Hutchison et al. 5738.
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articulated at the base, leaving a prominent peg from a sleeve ca.
0.5 mm long; pedicel scars irregularly spaced, often clustered, 0.5–
10 mm apart. Buds globose and becoming ellipsoid, the corolla
strongly exserted from the calyx tube before anthesis. Flowers all
perfect, 5-merous; calyx tube 1–1.5 mm, cup-shaped but abruptly
narrowing from the pedicel, the lobes 1.5–2 mm, broadly deltate
and irregularly splitting, pubescent at the tips with tiny dendritic
trichomes to 0.5 mm; corolla 1.9–3 cm in diameter, lilac, stellate
to stellate-pentagonal, lobed ca. halfway to the base, the lobes 8–
1064–7 mm, planar or slightly campanulate at anthesis, densely
papillate and pubescent at the tips and margins, the hairs
extending slightly along the midvein abaxially; filament tube
,0.2 mm, the free portion of the filaments 0.75–1.5 mm, glabrous
and shiny; anthers 4.5–561.5–2 mm, yellow, sagittate at the base,
poricidal at the tips, the pores lengthening to slits with age; ovary
glabrous; style 7–10 mm, glabrous and shiny; stigma capitate and
bifid, the surface minutely papillate. Fruit a globose berry, 1.2–
1.5 cm in diameter, black, the pericarp thin, dull and matte;
fruiting pedicels 1.6–2 cm long, ca. 7 mm in diameter at the apex
with the apex markedly more dilated, apparently nodding in fruit;
fruiting calyx lobes to 5 mm, woody, the margins paler. Seeds 4–6
per berry, 5.5–663–4 mm, flattened reniform, reddish brown, the
surfaces minutely pitted, the testal cells round-rectangular in
outline.
Distribution. Solanum sanchez-vegae occurs in cloud forest,
montane forest (‘‘ceja de selva’’ and ‘‘jalca’’) in the Andes of
northern Peru south of the Huancabamba Depression around the
middle Rı
´o Maran˜on valley, from 2500 to 3250 m.
Etymology. Solanum sanchez-vegae is named in honor of Don
Isidoro Sanchez-Vega (CPUN), whose comprehensive in-depth
knowledge of the flora of northern Peru was kindly and generously
shared with all who crossed his path.
Preliminary conservation status. Solanum sanchez-vegae has
a relatively narrow distribution, but within that it is relatively
common, and it occurs in some protected areas such as Parque
Nacional Abiseo.
Additional specimens examined. PERU.Amazonas:
Balsas-Leimebamba road, km 406, 4 Jun 1977, Boeke 1927 (MO);
Prov. Chachapoyas, 29 Jul 1991, Mostacero et al. 2619 (MO); Prov.
Chachapoyas, Atue´n, Chuquibamba, 18 Jul 1995, Quipuscoa &
Bardales 187 (BM, F, MO); middle eastern slopes, near kms 411–416
of Leimebamba-Balsas road, 11 Jul 1962, Wurdack 1314 (K, USM).
Piura: Prov. Huancabamba, Procedencia, Cruz Blanca-
Turnalina., 5 Sep 1981, Lo´pez M. & Ramı
´rez 8926 (BM). La
Libertad: Prov. Santiago de Chuco, Cerro La Botica, 9 Jun 1953,
Lo´pez M. 1011 (US); Prov. Santiago de Chuco, 14 Jun 1984,
Sagastegui et al. 11894 (MO); Prov. Sanchez Carrio´n, alrededores de
Huamachuco, 22 May 2001, Sagastegui & Zapata 16535 (BM); Prov.
Santiago de Chuco, 9 Jun 2001, Sagastegui et al. 16631 (BM, F); Prov.
Bolivar, junction of Quebrada Misquichilca and Quebrada
Quisuar, 4 km SE Condormarca, 7u009S, 77u009W, 5 Jun 1986,
Young 3554 (K, USM). San Martı
´n: Prov. Huallaga, valley of Rı
´o
Apisoncho [ = Abiseo] 30 km above Jucusbamba, 7u559S,
77u109W, 2 Sep 1965, Hamilton & Holligan 551 (K). Cajamarca:
Prov. San Miguel, en los alrededores, Dist. Unio´n Agua Blanca, 9
Feb 2000, Alvı
´tez I. et al. 1057 (F); Prov. San Ignacio, base de Cerro
Picorana, Dist. San Jose´ de Lourdes, 25 Aug 1999, Diaz et al. 10743
(MO); Prov. San Miguel, alrededores (Agua Blanca), 5 Jul 1986,
Mostacero L. et al. 1326 (BM, F); Prov. Contumaza´, sobre la ruta
Salcat, Cascabamba-Pampa de la Sal, 30 Jun 1983, Sa´nchez Vega
3142 (F, MO); Prov. Chachapoyas, (Agua Blanca), 12 May 1977,
Sagastegui et al. 8804 (MO); Prov. Contumaza´, Contumaza´-
Cascabamba, 12 Jun 1981, Sagastegui et al. 9994 (BM, MO); Prov.
Cajamarca, SAIS, Jose´ Carlos de Maria´tegui, km 20–40 on
Sunchubamba-San Juan road, 5 Jun 1984, Smith & Sanchez Vega 752.
Solanum sanchez-vegae is a striking species, with large purple
flowers and shiny rubbery leaves (Fig. 4). It has long been
subsumed in the more common and widely distributed S. aureum
Dunal, with which it is very similar. Solanum aureum differs from S.
sanchez-vegae in its smaller flowers, generally denser and more
congested pubescence of dendritic trichomes with many small,
short branches (as opposed to loose dendritic trichomes with larger
branches, see Fig. 3A) and more northerly distribution. The ranges
of S. aureum and S. sanchez-vegae slightly overlap in northern Peru,
but in general S. aureum is an Ecuadorian species. I have previously
identified specimens of S. sanchez-vegae as S. aligerum Schltdl., a
shrubby member of the Dulcamaroid clade with similar large,
open inflorescences, but S. aligerum has white flowers and tufts of
dendritic trichomes in the vein axils, rather than purple flowers
and dendritic trichomes along the veins. Solanum sanchez-vegae also
resembles the Venezuelan species S. dichroandrum Dunal, with
which it shares loose pubescence and relatively large flowers; it
differs from S. dichroandrum in its much larger (to 3 cm rather than
to 2.5 cm) purple flowers (Fig. 3D, 4), glabrous style (Fig. 3E) and
few-seeded berries.
Solanum sousae S. Knapp, sp. nov. [urn:lsid:ipni.org:
names:77103636-1] Type: Mexico. Oaxaca: Mun. San Miguel
Chimalapa, Cerro La Culebra, al N del Cerro Guayabitos, ca.
6kmlı
´nea recta al NO de Benito Juarez, ca. 42 km en lı
´nea recta
al N de San Pedro Tapanatepec, 16u459N, 94u119W, 1600–
1800 m, 16–18 Jul 1986, S. Maya J. 3602 (holotype, MEXU-
932219).
Figure 5.
Species Solano pyrifolio Lamarck similis, sed foliis aequaliter
pubescentibus, lobis calycis minutis, antheris inaequalibus, differt.
Woody vine with trailing stems; stems sparsely pubescent with
simple, uniseriate trichomes to 0.5 mm long, composed of 2–3
cells, the stems soon glabrescent; new growth densely pubescent
with simple uniseriate trichomes, these whitish cream; bark of
older stems pale greenish brown, glabrescent. Sympodial units
plurifoliate. Leaves simple, 2.7–7(+)61–5 cm, narrowly ovate to
elliptic, membranous, the upper surface glabrous to sparsely
pubescent with simple, uniseriate trichomes on the lamina, more
densely pubescent on the veins, the trichomes to 0.5 mm long, the
undersurfaces almost glabrous to densely pubescent with simple,
uniseriate trichomes to 0.5 mm long, these denser on the veins;
Figure 4.
Solanum sanchez-vegae
.Peru. La Libertad. A. Cano s.n.
(photograph courtesy of A. Cano, USM).
doi:10.1371/journal.pone.0010502.g004
New Vining Species of Solanum
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primary veins 5–7 pairs, yellowish; base truncate to broadly acute;
margins entire; apex acute to acuminate; petiole 1–4 cm, twining,
glabrous or pubescent like the adjacent stem. Inflorescence 7–
10 cm long, terminal, many times branched, more or less broadly
triangular in outline, with 30–40 flowers; peduncle 3–4 cm long,
pubescent like the stems; pedicels 1–1.5 cm, ca. 0.5 mm in
diameter at the base, ca. 1 mm in diameter at the apex, nodding at
anthesis, sparsely pubescent like the rest of the inflorescence,
articulated near the base, leaving a small peg ca. 1 mm high, on
the rhachis; pedicel scars spaced 0.1–0.5 cm apart, clustered near
the tips of the inflorescence branches. Flowers all perfect, 5
merous; calyx tube 1.5–2 mm, conical, appearing striped from the
thickened venation, the lobes ,0.5 mm, mere undulations on the
margin of the tube, occasionally somewhat quadrate when sinus
splitting, sparsely and unevenly pubescent with simple, uniseriate
trichomes to 0.5 mm; corolla 1.5–2 cm in diameter, white, stellate
to pentagonal stellate, lobed 1/2 to 3/4 of the way to the base, the
lobes 5–8 x ca. 4 mm, planar or slightly cupped at anthesis,
densely pubescent-papillate with minute simple trichomes abaxi-
ally, glabrous adaxially; stamens with the filament tube minute,
pubescent; free portion of the filaments 1.2–2 mm, very slightly
unequal in some collections, pubescent near the base adaxially
with tangled, simple uniseriate trichomes ca. 0.5 mm; anthers
2.5–361–1.5 mm, yellow, ellipsoidal, poricidal at the tips, the
pores lengthening to slits with age; ovary glabrous; style 7–9 mm,
pubescent with simple uniseriate trichomes ,0.5 mm in the lower
half; stigma capitate or somewhat bilobed, the surface densely
papillate. Fruit a globose berry to 1.5 cm in diameter, green
(immature?), the pericarp thin, matte; fruiting pedicels 1.5–1.7 cm,
ca. 1.5 mm in diameter, woody and pendent. Seeds .50 per
berry, ca. 2.562 mm, flattened reniform, golden brown, the testal
surface minutely pitted.
Distribution. Solanum sousae is known only from southern
Mexico in the states of Puebla and Oaxaca, in mesophyllous
forests and oak-pine-Liquidambar forests on steep slopes with rich
soils, from 1600–1900 m.
Etymology. Solanum sousae is named in honour of Mario
Sousa Sa´nchez (MEXU), whose dedication to the advance of
knowledge of the Mexican flora has resulted in a whole new
generation of Mexican botanists.
Preliminary conservation status. Solanum sousae is known
from only three widely dispersed collections, none of which falls
within a protected area. It must be considered at threat, but
further collecting and observation are a priority.
Additional specimens examined. MEXICO.Oaxaca:
Mpio. Santa Marı
´a Chimalapa, Cerro de los Pavos, al N de
Figure 5.
Solanum sousae
.A) portion of stem with flowering inflorescence, B) flower, C) flower cross section, D) anthers, E) portion of stem with
fruiting inflorecence. A–D drawn from Ventura 2212, E from Maya J. 3938.
doi:10.1371/journal.pone.0010502.g005
New Vining Species of Solanum
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Cerro Guayabitos y al O del Rı
´o Portemonedas, ca. 47 km en
lı
´nea recta al N de San Pedro Tapanatepec, 16u479N, 94u109W,
22–23 Sep 1986, Maya J. 3938 (MEXU). Puebla: Mpio.
Atempan, Puente Viejo, 1900 m, 8 Jul 1986, Ventura A. 22129
(MEXU).
Solanum sousae is superficially similar to S. pyrifolium Lam. of
Hispaniola, but differs from that species in its more broadly
triangular inflorescence outline (Fig. 5A), minute calyx lobes
without thickened margins (Fig. 5B) and in its lack of a prominent
submarginal leaf vein. The leaf pubescence of the two species is
very similar, but S. sousae is in general more densely pubescent on
the new growth and abaxial corolla surfaces. Solanum sousae differs
from the more common and sympatric S. dulcamaroides Poir. in its
white flowers, generally simple pubescence (versus more common-
ly dendritic in S. dulcamaroides), white rather than purple flowers,
and in its anthers that are not markedly thickened and rounded
abaxially.
It is likely that the juvenile leaves of S. sousae are pinnatifid, as
are those of most other species in this group; young foliage is only
very rarely collected and is often not associated with the flowering
stems with simple leaves.
Materials and Methods
Specimens
These new species came to light during the examination of
herbarium specimens during work on a monograph of the larger
Dulcamaroid group (see above). Taxonomic methods follow other
recent Solanum treatments [2,7,8]. All measurements are indicated
in the text and were taken from preserved herbarium specimens.
Specimens were examined from herbaria cited in text; herbarium
acronyms follow Index Herbariorum (http://sweetgum.nybg.org/
ih/).
Nomenclature
The electronic version of this document in itself does not
represent a published work according to the International Code of
Botanical Nomenclature [10], and hence the new names
contained in the electronic version are not effectively published
under that Code from the electronic edition alone. Therefore, a
separate edition of this document was produced by a method that
assures numerous identical printed copies, and those copies were
simultaneously distributed (on the publication date noted on the
first page of this article) for the purpose of providing a public and
permanent scientific record, in accordance with Article 29 of the
Code. Copies of the print-only edition of this article were
distributed on the publication date to botanical or generally
accessible libraries of the following institutions (BM, COL, GH,
HUA, K, MEXU, MO, NY, QCA, QCNE, USM). The separate
print-only edition is available on request from PLoS (Public
Library of Science) by sending a request to PLoS ONE, 185 Berry
Street, Suite 3100, San Francisco, CA 94107, USA along with a
check for $10 (to cover printing and postage) payable to ‘‘Public
Library of Science’’. In addition, new names contained in this
work have been submitted to IPNI (http://ipni.org), from where
they will be made available to the proposed Global Names Index.
The IPNI LSIDs (Life Science Identifiers) can be resolved and the
associated information viewed through any standard web browser
by appending the LSID contained in this publication to the prefix
http://ipni.org/.
The online version of this work is archived and available from the
following digital repositories: PubMedCentral (www.pubmedcentral.
nih.gov/) and Solanaceae Source: a web resource for the nightshade
family (http://www.solanaceaesource.org).
Acknowledgments
I thank the curators of herbaria cited in the text for loan of specimens;
Norman Robson (BM) for help with the Latin diagnoses; Bobbi Angell for
the line drawings; Asuncio´ n Cano (USM) for use of his photograph of S.
sanchez-vegae, and, together with Maria Isabel de la Torre (USM), for
hospitality in Lima; Clara Ines Orozco for help with finding specimens in
Colombian herbaria and verifying holotypes; Michael Nee (NY) and Lynn
Bohs (UT) for their enthusiasm in discussing Solanum taxonomy, and the
rest of the PBI Solanum team for support in many ways; Katherine Challis
and Alan Paton (K) for assistance with IPNI LSIDs and, with John McNeill
(E), for nomenclatural advice generally.
Author Contributions
Conceived and designed the experiments: SK. Performed the experiments:
SK. Analyzed the data: SK. Contributed reagents/materials/analysis tools:
SK. Wrote the paper: SK.
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