DIPLYCOSIA INDICA (ERICACEAE): A NEW SPECIES AND A NEW GENERIC RECORD FOR INDIA

2009·2.6 MB·English

by  M R Debta

DIPLYCOSIA INDICA (ERICACEAE):
NEW NEW
A AND A GENERIC RECORD FOR
INDIA
SPECIES
Chowdhery
Debta and
HJ.
M.R. 1
Botanical Survey ofIndia (Northern
Circle)
Kaulagarh Road, Dehradun-248 INDIA
192, 195,
INTRODUCTION
The genus Diplycosia consisting of about 99 species (Mabberley 1997), widely distributed in the Ma-
is
He
laysian region. Sleumer (1967) revised the genus for Flora Malesiana treating 97 species. reported that
the genus has highest diversity in Borneo, while Mt. Kinabalu has the highest concentration of species.
its
Powell and Kron (2001), based on molecular studies, have suggested treating Diplycosia under Gaultheria
— —
new
L. Argent (2002) while studying Diplycosia from Borneo and peninsular Malaysia described seven
species, one new form, and made two new combinations. Diplycosia can be distinguished from Gaultheria
with
the following key.
KEY TO THE GENERA AND GAULTHERIA
DIPLYCOSIA
Flowers in fascicles; anther cells unawned, not aristate, with short or long apical tubules at apex; tubules
1.
connate Diplycosia
or free
awned
Flowers in racemes; anther cells or aristate, not having apical tubules at apex Gaultheria
1
.
During a 2006 plant collecting expedition to Singalila National Park (West Bengal), in the eastern Himalayan
phytogeographic zone, some interesting and unusual plant specimens belonging to the family Ericaceae were
some
collected. Initially they were identified as species of Gaultheria, but detailed studies revealed that of the
unknown
specimens belonged to the closely allied genus Diplycosia, which is hitherto from India. Further
critical examinations of the specimens have shown that though one specimen had some resemblance to a
number
Malaysian species, Diplycosia aperta Sm., but differs widely from in habit, leaf venations, of
it
J.J.
new new
flowers, bracteoles, and calyx character. The collection therefore described as a species, Diplyco-
is
new
which shows with
sia indica, is also a generic record for India. Table 1 the differences its allied species
An new
Diplycosia aperta. illustration of the species provided for easy identification.
is
Terrestrial, prostrate shrubs, up to 1.5 mhigh. Stems terete, laxly to densely brown-hirsute or setose, reddish.
mm mm
Leaves subcoriaceous, 13-36 long x 7-18 wide, elliptic to ovate-elliptic, mucronate or apiculate,
Research Institute of Texas 3(1)
Debta and Chowdhery, A new species of Diplycosia from India
Table 1. Distinguishing characters of Diplycosia indica and D. aperta.
Margin with short cilia; lateral veins in VI ateral veins in 2 pairs,
3-4 beneath obscure beneath
pairs, distinct
mm,
(3-)4-6; pedicel 0.5 glabrous or rarely pedicel 0.8-1 cm, with bristles
2, 3; .1
1
mm mm
Acute to shortly acuminate, 3-3.5 long, Obtuse, ca. long, glabrous throughout
.5
1
very sparsely puberulous the apical the dorsal surface
in
half along midrib on dorsal surface
some
Minutely puberulous on both surfaces Glabrous to fine glandular warts on
apical portion dorsal surface
in
mm
rounded to broadly cuneate at base, margin serrulate-ciliate with short cilia, cilia 0.5-1 long, laxly softly
pilose at the base along mid-vein, dark green above, setulose, light green beneath; veins impressed above,
mm
3-4 up
distinct beneath, lateral veins in pairs; petiole 1.5-3 long, setulose, red. Inflorescence a fascicle,
mm mm mm
7 long, (3-)4-6-flowered, glabrous; bracts 1.5-2 long x 1.8-2.2 wide, basal, ovate, acute,
to
mm mm
glabrous, margin membranous, reddish-green; bracteoles 3-3.5 long x 1.3-1.8 wide,
ciliate, 2,
ovate, acute to shortly acuminate, opposite, concave, margin membranous, ciliate, very sparsely puberulous
mm mm
4-5
in the apical half along the middle on dorsal surface. Flowers long, urceolate; pedicel ca. 0.5
mm mm
long, inconspicuous, glabrous. Sepals 5-6, 1.5-3 long x 1-1.5 wide, ovate-triangular, acuminate,
minutely puberulous in the apical portion on both the surfaces, margin membranous, thickly puberulous,
mm mm
adnate to the ovary, rosy-pink. Corolla ca. 4 long, urceolate, white, 6-lobed; lobes ca. 0.7 long,
mm
ovate, apex obtuse to rounded, margin obscurely crenulate, glabrous. Stamens 10, ca. 1.5 long, loosely
mm
epipetalous, caducous, filament ca. 0.8 long, oblong, dilated at middle, papillose; anther with tubules
mm mm mm mm
0.6 long, very small, 2-lobed, oblong. Pistil 2.5-3.5 long; ovary superior, 1 long x 1.5 wide,
mm
subglobose, subglabrous or scattered puberulous, light green; style ca. 2 long, slender, sparsely minutely
hairy in upper half; disk cupular, 8-10 lobed, pressed against the ovary, papillose. Fruit not seen.
Diplycosia indica is closely allied to Diplycosia aperta J.J.Sm. but can be distinguished from it by its ter-
much
restrial habit; inflorescence with 4-6, glabrous pedicelled, smaller, white flowers; acute to acuminate,
puberulous and puberulous
sparsely bracteoles, calyx.
—
Habitat and Rare among scrubs on sub-alpine slopes, in association with Viburnum erubescens,
ecology.
3000
Thamnocalamus and an about m.
ferns altitude of
aristatus, etc. at
Flowering.—
June.
—
Distribution. India: Eastern Himalaya (West Bengal). Endemic.
—
named
country
Etymology. Diplycosia indica is after India, the of its origin.
—
Conservation The new species could not be traced from anywhere inside the Singalila Na-
status.
—
from Manebhanjeng
tional Park except for a small population. Since Singalila National Park especially to
—
Sandakphu a famous trekking route, attracts a large number of tourists and trekkers throughout the
is
it
year. The increasing pressure from the tourism industry and large scale cattle grazing in and around park
numerous
areas, are posing severe threats to the natural habitat of species including Diplycosia indica.
2JU]
The authors are indebted to the director, Botanical Survey of India for providing facilities. Grateful thanks
are due to G.C.G. Argent and Middleton, Royal Botanic Garden, Edinburgh for their expert suggestions
D.J.
new
and helps, to Nair, ex-joint director, Botanical Survey of India for providing Latin diagnosis of the
V.J.
species. Thanks are also acknowledged to the officials of the Forest Department, Government of West Bengal
permission carry out research work inside the Singalila National Park and to Brijesh Kumar, Botanical
for to
We
survey of India, Dehradun for illustrating the new species. greatly appreciate the helpful review of one
anonymous
reviewer.
Newtaxa and new combinations the genus Diplycosia (Ericaceae) of Borneo and Peninsular
Argent, G.C.G. 2002. in
Singapore 7-238.
Malaysia. Gard. 54:21
Bull.
Cambridge
Mabberley, DJ. 1997. The plant book: a portable dictionary of the vascular plants. University Press.
Pp. 234.
group
and 2001 An of the phylogenetic relationships the wintergreen {Diplycosia,
Powell, E.A. K.A. Kron. analysis in
.
26:808-81
Gaultheria, Pemettya, Tepuia; Ericaceae). Syst. Bot. 7.
Sleumer, H. 967. Diplycosia Blume. In: van Steenis, C.G.G.S, ed. Fl. Males. 6, ser. 1 :696-740.
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