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Botanical Journal of the Linnean Society (2000), 133: 343–357. With 21 figures
doi:10.1006/bojl.1999.0325, available online at http://www.idealibrary.com on
The Bornean Lithocarpus Bl. section Synaedrys
(Lindl.) Barnett (Fagaceae): its circumscription
and description of a new species
CHARLES H. CANNON∗AND PAUL S. MANOS
Duke University, Dept of Botany, Box 90339, Durham, NC 27705, U.S.A.
Received May 1999; accepted for publication November 1999
The Bornean species of Lithocarpus Bl. section Synaedrys (Lindl.) Barnett (Fagaceae) are discussed
in terms of their unifying characteristics, and keys to the species are provided. A novel
morphological feature present in the genus, where the seed in the mature fruit is enclosed
by a lignified and thickened receptacle, is illustrated. A new species, L. palungensis Cannon
& Manos, is described. It can be distinguished from L. pulcher (King) Markgr. by its submontane
distribution, prominent reflexed cupular spines, present at all stages, and broadly oblong
leaves with scattered open fasciculate trichomes on the abaxial surface. Foliar trichome types
present within the section are also described. Distinctiveness of fruit wall and receptacle
shape, as described by two-dimensional elliptic Fourier transformation, is demonstrated by
principal components analysis.
2000 The Linnean Society of London
ADDITIONAL KEY WORDS:—Castaneoideae – cupule – elliptic Fourier analysis – fruit
morphology – Indonesia – Malaysia – receptacle – trichomes.
CONTENTS
Introduction ....................... 343
Methods and material ................... 345
New species description ................... 346
Keys to the species .................... 349
Results and discussion ................... 352
Specimens cited ..................... 356
Acknowledgements .................... 357
References ....................... 357
INTRODUCTION
The genus Lithocarpus (Fagaceae) ranges from eastern India through southern
China, north to Japan, and extends through south-east Asia, across the Malayan
archipelago to Papua New Guinea (Soepadmo, 1972): a large range covering a large
∗Corresponding author. Email: chc2@duke.edu
343
0024-4074/00/070343+15 $35.00/0 2000 The Linnean Society of London
C. H. CANNON AND P. S. MANOS344
number of biogeographic regions. Lithocarpus comprises over half of the subfamily
Castaneoideae ( Jones, 1986) and includes more than 250 species. One relictual
species, Lithocarpus densiflorus (H. & A.) Rehd., is found in the Pacific northwest,
U.S.A. (Camus, 1948). Fruit and cupule morphology, the most salient feature for
taxonomic identification (Camus, 1952–54), is reminiscent of the acorn in Quercus
L., with each flower seated in a valveless cupule or ‘flower-cupule’ (Forman, 1966a).
Within Castaneoideae, this feature is unique because both Castanopsis Spach. and
Castanea Miller generally have ‘dichasium-cupules’ or more than one flower seated
in each cupule (although secondary reduction to a single flower does occur within
Castanopsis and Castanea). This pattern, where several characters in combination are
diagnostic for a group but each individual character appears with other characters
in different combinations, is common for morphological features within the family.
This high degree of convergent evolution presents a great challenge to generic
delimitation of Fagaceae (Forman, 1966a).
Within the ‘flower-cupule’ syndrome of Fagaceae, the diversity of fruit and cupule
morphology is highest within Lithocarpus (Kaul, 1987). Camus (1952–54) recognized
13 subgenera on fruit and cupule morphology; one, the Castanopsis ‘fissa’ group of
Barnett (1944), was mistakenly placed in subgenus, Pseudocastanopsis (Forman, 1966b).
Several of these subgenera are composed of few species with limited geographic
distribution and vague morphological distinction, and are of limited taxonomic and
phylogenetic utility. Identification of monophyletic lineages within such a large and
difficult group is the first step towards performing more detailed phylogenetic
analyses. Little work at the sectional level within the genus has been performed
(Kaul, 1986, 1987).
Although the Bornean species of Lithocarpus cannot be considered monophyletic,
many are endemic (Soepadmo, 1970) and together they encompass much of the
fruit and cupule variation present in the genus. Lithocarpus section Synaedrys represents
one possible monophyletic group. As defined by Camus (1952–54), the 15 species
have a disjunct distribution, with the highest level of diversity found in south-east
China and Vietnam. The island of Borneo is another centre, with four species, and
additional disjunct species are found in the Philippines and Papua New Guinea. No
collections of the section exist from Thailand and peninsular Malaysia.
The name Synaedrys was first introduced at the generic level (Lindley, 1836) and
later considered at the sectional level with 35 species (Barnett, 1944). Although no
diagnostic description was provided, the following couplets were used to identify the
species of section Synaedrys: “Cupule not longer than the glans; Cupule covering the
glans completely except for the umbo and styles; Cupule more or less completely
fused with the glans” (Barnett, 1944: 179). This definition is too broad and would
undoubtedly lead to the recognition of a polyphyletic assemblage.
Camus (1952–54) provided a narrower definition for Synaedrys at the subgeneric
level and placed Barnett’s constituent species into eight separate subgenera. Her
definition is sufficiently useful to be translated here:
Cupules large, thick, woody, sessile, indehiscent, sometime several fused together, mostly
enclosing the fruit but leaving the apical part free, ordinarily concave, with large scales,
sometimes knobbed, fruit ordinarily large, fused partially to the cupule, the fruit wall thick,
woody, the apical part free, slightly raised, flat or impressed, the false septa hard, often well
developed, profoundly dividing the seed, the abscission scar very high, hemispheric or
BORNEAN LITHOCARPUS SECT. SYNAEDRYS (FAGACEAE) 345
INDONESIA
BRUNEI
MALAYSIA
L. pulcher
L. palungensis
L. echinifer
L. rotundatus
Figure 1. Distribution map of the Bornean species of Lithocarpus section Synaedrys (Fagaceae). Asterisks
indicate field locations visited as part of this study.
convex, often rough, often furrowed (in the form of empty ships), the cotyledons lobed,
sometimes profoundly, styles long or slightly so (Camus, 1952–54: 609).
With this paper, we first describe a new species and discuss the other Bornean
species of Lithocarpus section Synaedrys. On the basis of morphological studies, a suite
of potentially diagnostic features for the section across its geographic distribution is
derived. A novel morphological feature confined to the Castaneoideae but scattered
among species in both Castanopsis and Lithocarpus is introduced. Patterns of variation
within internal fruit morphology provide objective diagnostic characters for Synaedrys,
thus avoiding apparent but mistaken problems of convergent evolution in phylo-
genetic analyses.
METHODS AND MATERIAL
Herbarium loans from A, L, and KUC have been examined, as well as collections
at FRIM and BOG. Fallen nuts, leaves, and herbarium specimens for all species
discussed here were collected at numerous locations around the island (Fig. 1).
C. H. CANNON AND P. S. MANOS346
Mature nuts were cut along a radial plane of symmetry through the stylar column
on either an electric table saw or with a small handsaw. Images perpendicular to
the dissection plane of the mature nuts were captured using a Burle analog camera
mounted with a Nikkor 55 mm lens. Images were saved as TIFF format files, using
Image1 software (Universal Imaging Corp. 1991). After image capture, an orientation
bar several pixels thick was placed upon the image in Canvas 5 (1997). The ends
of the bar were placed upon the point where the proximal ends of the fruit wall
meet the cupule. The bar and the image were rotated together until the bar became
parallel to the coordinate system of the image. Correct orientation of the fruit axis
is important because shape changes in tissue outline are subtle and much of the
overall configuration of the tissues is contained in their relationship to the fruit axis.
This image was then printed and tissue outlines were traced, verifying the tissue
boundaries in the image against those in the original specimen. The orthogonal
orientation of the image was preserved in relation to the edges of the paper. Tracings
of the tissue outlines were then scanned and imported back into Image1 to produce
a list of (x,y) coordinates. These steps were necessary because no automatic adjustment
was sufficient to distinguish tissue boundaries within the original image.
The coordinate lists were then passed through a two dimensional elliptic Fourier
analysis (EFA; Rohlf, 1990). Lists originated on the left side of each outline, at the
point where the orientation bar was anchored. Outlines reconstructed with these
coefficients were compared against the original outline obtained from the specimen,
to ensure accuracy of reproduction. Mean outline shape for a species was obtained
by averaging the corresponding coefficients at every harmonic for each nut of that
species (McLellan & Endler, 1998). For principal component analysis of covariance,
the first five and seven harmonics of the EFA descriptors of the fruit wall and
receptacle, respectively, were used.
Scanning electron micrographs (SEM) were taken of small leaf fragments from
numerous individuals of each species, mounted on stubs with double-sided tape and
sputter-coated with 60% gold/40% palladium. Both abaxial and adaxial surfaces
were examined under various levels of magnification on a Philips 501 scanning
electron microscope to detect differences among species. Images were stored directly
into TIFF format files using Printerface (GW Electronics, Inc.).
NEW SPECIES DESCRIPTION
Lithocarpus palungensis Cannon & Manos sp. nov. TYPE: Malaysia. Sarawak,
Bario, Ulu Baram, path to Pa’Umor. 1170 m, 26.vi.1964, J.A.R. Anderson S20119
(holotype, AA; isotypes, K, L, A, SAN).
Illustration. Figure 2. Arbor grandis sylvae submontanae a L. pulchro, specie affini
sed non montana, foliis late oblongis venis secundariis numerosis arcte parallelis,
trichomatibus erectis fasciculatis in pagina abaxiali sitis cupulis non profundis,
obconicis, squamis prominentibus densis reflexis armatis differt.
T: large, 20–35 m tall, 25–65 cm dbh, steep plank buttresses to 1 m in height
to low thick rounded buttresses, bole often slightly convoluted and twisted, first
limbs branching low on the bole and spreading broadly, crown open. B: pale
grey to dark brown, becoming ashy and corky upon drying; flaking irregularly,
eroded ends of the flakes raised and curled, 4–6 cm long, 0.5–2 cm wide, sometimes
BORNEAN LITHOCARPUS SECT. SYNAEDRYS (FAGACEAE) 347
2 cm
2 cm
3 cm
A
C
B
Figure 2. Lithocarpus palungensis Cannon & Manos, sp. nov. A, fruiting stem with mature cupule
and newly expanding vegetative bud, J.A.R. Anderson S.20119. B, mature cupule showing detail of
cupular scales, C.H. Cannon 769. C, infructescence with several immature fruit, Haji Suib S.29702.
with large scattered lenticels on the under bark, singular, large, and irregularly
raised. B: of various ages being covered with minute, dense, many-armed,
darkly rufous, slightly resinous, stellate hairs (>10×mag. required) until hairs
become much worn, dark grey to black, irregular, and indistinct; dark grey beneath
hairs with no obvious lenticels. L: evergreen, stiffly coriaceous, 13–30 cm long,
8–13 cm across, broadly elliptical to oblong, leaf margin slightly and irregularly
undulate, base broadly obtuse to rounded, sometimes becoming slightly folded, apex
often irregularly eroded, being shortly acuminate to broadly cuneate when complete,
often slightly folded. Midrib very prominent and raised on both sides, never grooved,
C. H. CANNON AND P. S. MANOS348
densely pubescent. Secondary veins numerous, 15–20 pairs, obscure but visible
adaxially, raised and prominent abaxially, arising at 65–80°to the midrib, the first
proximal veins perpendicular and much closer to one another than more distal
veins, the last distal veins highly curved and anastomosing at the margin, all veins
bending sharply near the margin with a long trailing end remaining roughly parallel
to margin, vanishing gradually. Tertiary veins rather obscure on both sides, always
perpendicular to secondary veins, never dividing. Adaxial surface light brown to
dark reddish-brown, glabrous, dull burnished appearance, waxy cuticle sometimes
slightly glaucous. Abaxial surface light to dark yellowish-brown, densely covered
with minute fused slightly resinous stellate hairs, the modified type 7 or fused type
9 of Jones (1986), occasionally becoming tectate, occasionally with erect ‘open’
fasciculate hairs (type 5) scattered over surface, particularly common near the veins
and midrib. Stipules 5–7 mm long, 2–3 mm wide, lanceolate, acuminate apex,
broadest at the base, armed with minute dense silvery to rufous, many-armed, ‘open’
fasciculate hairs abaxially, caducous, leaving prominent, elliptical scars perpendicular
to branch axis, 2–3 mm long. Petiole 1–2 cm long, 3–8 mm across, terete, broadly
thickened to three-quarters length, slightly curved, smooth with no sign of twisting
or shrinking upon drying, slightly flattened to grooved adaxially, dark grey-black,
covered with much worn irregular hairs. S : not seen.
P : one flower per cymule along the rachis, perianth with
six fused to slightly imbricate lobes and three shortly acuminate styles. P
: robust, armed with hairs as branchlet, 5 mm thick, round in cross-
section, 1–7 fruited. Immature cupule fringed basally with papery, fused, five-lobed
bract, fully enclosing immature fruit, densely set (less so proximally) with basally
thickened spirally arranged conical 2–3 mm scales, rather terete in cross-section,
distal scales closely adpressed and crowded, blunt and rounded, proximal scales
becoming erect and sharply acuminate, all scales darkly lustrous. M :
shortly pedicellate, obconical to rounded hemispherical, 4–5 cm across, 2.5–4 cm
tall, covering the nut for half of its length, woody, hard, the apical opening as broad
as the nut, deeply rounded inside with grooved margin between receptacle and
cupule tissue, cupule extending 3–5 mm beyond remnant receptacle, densely armed
with basally thickened and fused scales outside, sharply acuminate, curved, and
erect, lost with age becoming roughly turbeculate, ground color dark grey-black,
tips of scales silvery-grey to whitish. M : 3–4.5 cm across, 1.5–2.5 cm
tall, subhemispherical, abscission scar from receptacle broadly convex, slightly rugose,
receptacle tissue almost entirely enclosing seed, very hard, 3–4 mm at thinnest point,
central axis prominent and invaginated 5–10 mm, false septa not well developed
and mostly papery, ovary wall forming a lip 1–2 mm broad around edge, external
surface initially covered with minute clear appressed hairs, becoming glabrous and
dull burnished. Cotyledons free, deeply lobed and invaginated irregularly by papery
pericarp.
Distribution and ecology. Submontane forests above 700 m elevation on oligotrophic
soils, collected from the Kelabit Highlands and Kapit regions of northern Sarawak,
Malaysia and Gunung Palung, West Kalimantan, Indonesia.
Paratypes. Malaysia. Sarawak. Sungai Spanggil, Kapit, 3rd Division, 27. ix. 1969,
Haji Suib S29702 (KCH – wood sample no. 6393).
BORNEAN LITHOCARPUS SECT. SYNAEDRYS (FAGACEAE) 349
Figures 3–6. Foliar trichomes in Lithocarpus sect. Synaedrys (Fagaceae). Scale bar=1m. 3. L. echinifer,
‘fingers in a glove’ a
`la Camus, thick-walled appressed hairs with four digits fused basally and radiating
to one side are sparsely scattered among thin-walled, four-lobed, collapsed globular hairs, W. Meijer
24792. 4. L. rotundatus, four and two armed thick-walled appressed hairs with scattered thin-walled,
four-lobed, collapsed globular hairs, C.H. Cannon 548. 5. L. pulcher, indistinct appressed hair types with
long tangled arms, C.H. Cannon 630. 6. L. palungensis, indistinct tangled hairs and tectate waxy
cuticle, C.H. Cannon 655.
KEYS TO THE SPECIES
Herbarium key to the subsections and species of the Bornean Synaedrys (see Figs
3–10 for illustrations of trichomes and leaves).
A. Leaves with 6–12 secondary veins, visible but not prominently raised on both
sides, arising at a low angle from the midrib (45–60°), curving smoothly near the
margin. Under SEM, the thick-walled trichomes are mostly four-armed, scattered
on the lower surface, some fused forms present, the tuberculate waxy cuticle
visible with thin-walled four to two-lobed globular multicellular hairs. ....
..................Sub-section Echinocalyx A.Camus
C. H. CANNON AND P. S. MANOS350
Figures 7–10. Leaves in Lithocarpus sect. Synaedrys (Fagaceae). Abaxial surface of leaf shown in centre of each illustration, adaxial to either side. Scale bar=5 cm.
7. L. echinifer,C.H. Cannon 717. 8. L. rotundatus,C.H. Cannon 555. 9. L. pulcher,C.H. Cannon 702. 10. L. palungensis,C.H. Cannon 768.
BORNEAN LITHOCARPUS SECT. SYNAEDRYS (FAGACEAE) 351
B. Mature fruits elliptical in radial section, small (2–4 cm diameter), persistent style
sitting on a rather high umbo, cupule rather thin to slightly woody, enclosing the
nut entirely and dehiscing irregularly, with reflexed, brittle spines. Found in
lowland coastal area. ...................L. echinifer
B1. Mature nuts obconical in radial section, large (4–6 cm), cupule thick, enclosing
the nut entirely, indehiscent or breaking up like charcoal, set with short, hard
spines, with rather swollen bases. Found in submontane forests. . . L. rotundatus
A1. Leaves with more than 10 secondary veins, visible and prominently raised
below, arising at a high angle from the midrib (greater than 75°), running nearly
straight and parallel to one another until bending sharply near the margin. Under
SEM, the thick walled hairs are densely tangled, with many fused forms, cuticle
mostly hidden, trichomes secreting a tectate layer. Sub-section Pulchrae A.Camus
C. Cupule thick, the margin tightly appressed to the nut and thickened, spines
reduced, basally fused and indistinct. Without erect fasciculate hairs visible under
a hand lens. Found in the lowland forest. ...........L. pulcher
C1. Cupule thin, brittle, the margin relaxed at maturity, spines 3–6 mm long and
reflexed, present at the earliest stages of development, the spines almost distinct
from one another. Open erect fasciculate hairs visible under a hand lens near
the midrib and secondary veins. Found in submontane forests. . . L. palungensis
Field key to the Bornean Synaedrys
A. Lowland tree below 500 m elevation.
B. Low rounded to small plank buttresses present. Outer bark with many prominent
1 cm lenticels emerging in lines which anastomose and turn into cracks, dark
brown, rather smooth with some singular well spaced horizontal lenticels. Leaves
chartaceous, the 5–8 secondary veins not prominent, arcuate, petiole straight,
1.5–2 cm long by 2–2.5 mm wide. ..............L. echinifer
B1. Many high thick steep plank buttresses often present (to 2 m tall), spreading
without dividing. Outer bark dark brown, deeply cracked, fissured and thick;
sometimes breaking superficially into small flakes with raised blunt ends, large
lenticels present on underbark. Leaves thick coriaceous, the 10–15 secondary
veins prominent and raised below, often distinctly glabrous lustrous brown against
silver-white lamina, petiole 1.5–2 cm long by 3–6 mm wide, often slightly curled.
...........................L. pulcher
A1. Submontane tree between 700 and 2000 m elevation.
C. Large well formed tree with straight bole and steep, thick, spreading plank
buttresses. Outer bark whitish gray with many small lenticels in irregular lines,
cracking slightly. Leaves chartaceous, apex acuminate to acute, the 6–9 secondary
veins not prominent, arcuate, petiole 1–2 cm long by 3–4 mm wide. L. rotundatus
C1. Tree often leaning and twisted, first limbs branching low and spreading, steep
plank buttresses to 1 m in height to low thick rounded buttresses. Outer bark
pale grey to dark brown, flaking irregularly, eroded ends raised and curled,
4–6 cm long, 0.5–2 cm wide, sometimes with large scattered lenticels on the
under bark, singular, large, and irregularly raised. Leaves thick coriaceous, the
10–20 secondary veins prominent and raised below, covered with dense minute
rufous slightly resinous hairs, petioles 1–1.5 cm long by 4–7 mm wide, straight.
..........................L. palungensis
C. H. CANNON AND P. S. MANOS352
Figures 11, 12. Two main fruit types of Lithocarpus (Fagaceae) in radial section. The cupular receptacle
‘cr’remains inside the cupule ‘c’after dispersal of the nut, while the fruit receptacle ‘fr’seals the carpel
cavity. The fruit wall ‘fw’forms the upper part of the nut, between the style and the edge of the
cupular receptacle. 11. L. enclesiacarpus (sect. Cyclobalanus): the fruit receptacle is small and most of the
external part of the nut, when removed from the cupule is formed by the fruit wall, C.H. Cannon 70.
Scale bar=10 mm. 12. L. pulcher (sect. Synaedrys): much of the external part of the nut, when removed
from the cupule, is composed of receptacle and the fruit wall remains perpendicular to the central
axis of the fruit, C.H. Cannon 702. Scale bar=35 mm.
RESULTS AND DISCUSSION
The spatial relationship between fruit wall and receptacle in the mature nut
captures most of the morphological features which have been used to circumscribe
Lithocarpus section Synaedrys. The receptacle layer does not merely lie at the base of
the mature fruit, as it does in oaks (Quercus L.) and many other Lithocarpus, particularly
sections Pasania Miquel and Cyclobalanus A.Camus, but instead encloses the seed
(Figs 11, 12). The abscission scar between the fruit and cupule in all members of
the section is large, hemispherical, and rugose (Figs 13–16). Unfortunately, the
‘enclosed receptacle’fruit type, as described here, is also found in other sections
within the genus and Castanopsis as well, although consistent differences in shape
variation exist. Additionally, in section Synaedrys, proliferation of pericarp layers
between the fruit wall and receptacle around the perimeter of the fruit creates a
‘shoulder’or rim. The presence of this shoulder may be diagnostic but the degree
of development varies among taxa and individual specimens (Table 1). This feature
is also present in L. sericobalanus E.F.Warb., normally placed in section Cyclobalanus
because of its lack of cupular spines and the presence of lamellae (Camus, 1952–54),
suggesting this taxon may belong to section Synaedrys, as well. Although the degree
of enclosure of the nut by the cupule varies in the section, all of its members possess
prominent, imbricate, erect to squamose scales (Figs 17–20).
The highly lignified receptacle layer obviously provides mechanical protection
against seed predation. At what stage of development this protection begins, whether
at the earliest stages of ovule formation or after dispersal of the mature fruit, is not
known but the spatial relationship of the receptacular tissue to that of the ovary
wall appears to remain constant through development (see fig. 21c in Soepadmo,
BORNEAN LITHOCARPUS SECT. SYNAEDRYS (FAGACEAE) 353
Figures 13–16. Mean outline shapes of fruit walls and receptacles in Lithocarpus sect. Synaedrys (Fagaceae).
Outlines shaded black are fruit awlls and outlines shaded grey are fruit receptacles. Orientation of
shapes is identical to Figures 11, 12. Scale bar=5 mm. 13. L. echinifer. 14. L. rotundatus. 15. L. pulcher.
16. L. palungensis.
T 1. Unifying characteristics of the Bornean subsections and species within Lithocarpus section
Synaedrys (Fagaceae). Features in italics are found in other groups within the family, underlined are
diagnostic
Section
Synaedrys (Lindley) Barnett
No. of female flowers/cymule
1
1
Woody receptacle enclosing seed Present
Nut ‘shouldered’Yes
Sub-section Sub-section
Echinocalyx A. Camus Pulchrae A. Camus
Leaf texture Chartaceous Thick coriaceous
Leaf venation 5–10 pairs 15–20 pairs
Visible but not raised Prominent and raised
Foliar trichome Type 9 –four digits, distinct Type 9 –long digits, tangled
SEM
2
‘Fused’type 9 –many digits, rare ‘Fused’type 9 –scattered, common
Type 17 –four-lobed, constant Type 17 –rare
Cupule closure Complete Half
Irregularly dehiscent Indehiscent
L. echinifer L. rotundatus L. pulcher L. palungensis sp. nov.
Distribution Northern coastal Northern Southern and Southern
lowlands submontane western lowlands submontaine
Cupule scales Well-spaced Well-spaced Closely spaced Closely spaced
erect and reflexed reduced and fused reduced erect and reflexed
Foliar trichome Absent Absent Absent Type 5 –scattered,
SEM
2
solitary
1
Also noted by (Kaul, 1987),
2
( Jones, 1986).
C. H. CANNON AND P. S. MANOS354
Figures 17–20. Cupule types in Lithocarpus sect. Synaedrys (Fagaceae). 17. L. echinifer,W. Meijer 24792.
18. L. rotundatus,C.H. Cannon 555. 19. L. pulcher,C.H. Cannon 704. 20. L. palungensis,C.H. Cannon
768. Scale bar=2cm.
1972). The maintenance of spatial relationship of gynoecial tissue through de-
velopment, from flower to mature fruit, is different than the pattern found in oaks
and several other sections of Lithocarpus. In these other groups, the seed develops
above the receptacle, greatly expanding the ovary walls. The development of the
receptacular tissue is terminated early in development of the fruit and merely seals
the basal opening of the carpel cavity. In section Synaedrys, the receptacular tissue
proliferates along with the cotyledons of the embryo, and the fruit wall and pericarp
are reduced to the function of closing the apical part of the cavity. Changes in
developmental pathways of various tissues (Takhtajan, 1972) and the transfer of
protective function between tissues are a powerful source of evolution in this genus.
Given these potentially diagnostic features of fruit morphology for the section,
some species originally included by Camus will not fall within our narrower
circumscription. Many of the features she used are found among other sections and
genera and the transitional boundaries are not clear (Table 1). These features are
primarily overall fruit dimension, partial to complete enclosure of the nut by the
cupule, and the presence of thick scales. She also suggested that more than one fruit
can be found in a single cymule but no Bornean species exhibit this characteristic
(Kaul, 1987, pers. obs.). These characters have apparently undergone convergent
BORNEAN LITHOCARPUS SECT. SYNAEDRYS (FAGACEAE) 355
–0.8
0.2
pulcSK
–0.6 –0.4 –0.2 0 0.2 0.4 0.6
–0.6
–0.4
–0.2
0
pulcSK
rotuSB
pulcSK
pulcSK
pulcSK
pulcSK
pulcSK
paluKH
pulcSKpaluKH
paluKH
paluKH
paluKH
rotuKH
rotuSB
paluKH
rotuSB
rotuSB
rotuSB
rotuSB
rotuSB
echiLB
echiLB
echiLB
echiLB
echiSB
echiSB
echiSB
rotuSB
Figure 21. Species scores on the first two principal components analysis of the outline shape of fruit
wall and receptacle. The first five and seven harmonics of a two dimensional elliptic Fourier
transformation of the respective tissues were used; 65% of total variance is described by the first two
axes.
evolution, perhaps numerous times, within the genus, and we have attempted to
provide a more objective and stable definition of the group.
The usefulness of outline shape analysis of the fruit wall and receptacle layers in
radial section is demonstrated by the minimal overlap among species scores on the
first two axes of a principal components analysis of covariance (Fig. 21). The two
populations of L. echinifer, one along the eastern coast of Sabah and the other from
the northwest coast of Sarawak, are well separated along the second axis, suggesting
that infraspecific variation may be pronounced within this species. Although adequate
material was not available for the three other species, geographically distant in-
dividuals do not exhibit the same degree of distinctiveness. All of the samples of L.
echinifer obtained from the northwest coast of Sarawak were found in the Lambir
Hills National Park. This evidence supports the potential distinctiveness of the flora
within that protected area.
Lithocarpus palungensis can be distinguished from the closely related Lithocarpus pulcher
(both placed here in the subsection Pulchrae) by the reflexed erect scales on the
cupule and the more oblong, thicker leaves with more secondary veins (Figs 7–10,
17–20). The scales in the latter species are never erect or reflexed, even at the
earliest stages of development. The abaxial leaf surfaces of the new species generally
appear more rufous in color and have scattered erect ‘open’fasciculate hairs (type
5 trichomes of Jones, 1986), particularly near the secondary and primary veins.
The two species are quite distinct ecologically. Lithocarpus pulcher never occurs
above a few hundred metres in elevation and usually on rather deep sedimentary
derived soils while the new species is found above 700 m elevation on thin podzolic
C. H. CANNON AND P. S. MANOS356
soils of ridges and saddles. Both trees are poorly formed, often leaning with twisted
boles, but the new species has less free bole (less than 10 m) and the branches spread
widely.
The ecological distinctiveness of the new species was first noticed in the Gunung
Palung National Park, West Kalimantan, Indonesia, thus the specific epithet. The
research site includes a number of different forest types, from lowland peat swamp
to submontane moss forests. These types are all contiguous within a few square
kilometres, therefore ample opportunity for seed dispersal among forest types exists.
L. pulcher is a prominent member of the flora on low elevation mixed alluvial soils,
becoming quite large and producing large amounts of fruit at various times of the
year. The new species is only found on submontane exposed rocky ridges with some
level of peat development. The mid-elevational zone (200–600 m) is dominated by
granite-derived soils on moderate slopes and neither species is present in this
zone (Webb, 1997). Thus, despite few apparent morphological differences on first
examination, the prominent reflexed cupular spines and oblong leaves with strong
parallel venation are markers of a clear taxonomic entity.
Individuals of the new species were also seen in the expansive Kelabit Highlands
on relatively deep soils and collections exist from the upper reaches of the Rajang
River (Fig. 1). The species is not restricted to the coastal Palung range but extends
along the western slopes of the numerous inland mountain ranges. These latter
populations are far removed from any potential contact with L. pulcher in the coastal
lowlands. Also, the distribution of these two species in subsection Pulchrae overlaps
little with the other two species in subsection Echinocalyx. The former species are
restricted to the western and north-western parts of the island and are absent from
Lambir Hills National Park and Sabah, Malaysia. The latter two species (L. echinifer
and L. rotundatus), on the other hand, are found primarily in Sabah, Malaysia, with
L. echinifer frequently collected along the eastern coast. L. rotundatus is a rare tree,
seldom collected, and only a single population of trees was found on the western
slopes of Mt Kinabalu, although collections have been recorded from the Philippines
and Java (Soepadmo, 1970, 1972). This rare and unusual species is therefore the
most widely distributed, yet little herbarium material exists. The collections of L.
rotundatus made during the course of this study possess much larger fruit than the
type material, but identical leaf and internal fruit morphology do not support its
taxonomic distinctiveness.
SPECIMENS CITED
L. echinifer. Brunei—P.S. Ashton BRUN36; Sabah—W. Meijer 24792, M.A. Mujim
40664, Termiji Arshid 88628, Amin & Mansus 15668, Patrick P. Sam 39494, L. Madani
93721, Michael Anak 25223, G.H.S. Wood 3456, A.D.E. Elmer 20640, W. Meijer 20527,
Kadir 1722, G.H.S. Wood 4710; Sarawak—C.H. Cannon 717 and 718.
L. palungensis—Sarawak—J.A.R. Anderson S.20119, Haji Suib S.29702, H.P. Noot-
eboom 2149, C.H. Cannon 628, 655, 657, 658, 768, and 769.
L. pulcher—Brunei—P.S. Ashton BRUN8; Sarawak—Chew Wee-Lek 630, E.C. & L.B.
Abbe 12015, E.C. & L.B. Abbe 10241, Salleh anak Tada 12220, J.A.R. Anderson 29313,
E.C. & L.B. Abbe 9862, E. Soepadmo 27607, J. Burley et al. 257, J.A.R. Anderson 13395,
Bojeng Sitam 15061, Salleh anak Tada 12291, C.H. Cannon 630, 652, 694, 695, 697,
698, 702, 704, and 705.
BORNEAN LITHOCARPUS SECT. SYNAEDRYS (FAGACEAE) 357
L. rotundatus—Sabah—Francis Sadau 49504, W. Meijer 131970, C.H. Cannon 548 and
555; Sarawak—Ilias Paie 28579.
ACKNOWLEDGEMENTS
Funding for this project was provided by the A. W. Mellon Foundation through
a training grant awarded to the Department of Botany, Duke University, fellowships
from the Agency for Educational Development, the Center for International Studies
of Duke University, the American Society of Plant Taxonomists awarded to CHC
and NSF grant DEB-9707945 awarded to PSM. Indonesian sponsorship was provided
by the Center for Research and Development in Biology of the Indonesian Institute
of Sciences (PPPB/LIPI) and the Director General of Forest Protection and Nature
Conservation (PHPA) of the Ministry of Forestry, Indonesia. Sponsorship in Sarawak
was provided by the Institute for Biodiversity and Environmental Conservation at
the University of Malaysia, Sarawak and the Department of Forestry, Malaysia.
Sponsorship in Sabah was provided by Sabah Parks. We would like to thank the
personnel at the Sarawak Herbarium in Kuching and the Kinabula Park Head-
quarters, Sabah. C. O. Webb and J. Tarawe provided instructive discussion in the
field. W. L. Culberson provided the Latin diagnosis. C. Zartman provided the hand-
drawn illustration. Two anonymous reviewers and the editor provided valuable
corrections to the manuscript.
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