Distribution of six little known plant
species from Arunachal Pradesh, India
S.S. Dash 1 & A.A. Mao 2
Botanical Survey of India, Arunachal
Pradesh Regional Centre, Itanagar, Arunachal Pradesh 791111, India
Email: 1 ssdash2002@yahoo.co.in
(corresponding author),
Date of publication (online): 26 September 2011
Date of publication (print): 26
September 2011
ISSN 0974-7907 (online) | 0974-7893
(print)
Editor: P. Lakshminarasimhan
Manuscript details:
Ms # o2688
Received 31 January 2011
Final received 13 August 2011
Finally accepted 29 August 2011
Citation: Dash, S.S. & A.A. Mao (2011).
Distribution of six little known plant species from Arunachal Pradesh, India. Journal of Threatened Taxa3(9): 2095–2099.
Copyright: © S.S. Dash & A.A. Mao 2011. Creative
Commons Attribution 3.0 Unported License. JoTT allows unrestricted use of this
article in any medium for non-profit purposes, reproduction and distribution by
providing adequate credit to the authors and the source of publication.
Acknowledgements: The
authors are grateful to Director, Botanical Survey of India, and Kolkata for
encouragement and facility.
Arunachal
Pradesh being a part of the Himalaya-East Himalaya biogeographic zone (Rodgers
et al. 2000) is also the confluence point of three biogeographic realms,
namely, the Afro-tropical, the Indo-Malayan and the Indo-Chinese (Takhtajan
1969). It harbours a unique
composition of different plant communities, influenced by various factors
including rainfall, temperature, humidity and altitude (Biswas 1966). The biodiversity of Arunachal Pradesh
is supported by a wide range of endemic species and various fragile
ecosystems. More than 82% of the
geographical area of the state is covered with forests, which are the
custodians of c. 29% flowering plants of India (Hajra & Mudgal 1997).
During
the recent floristic survey conducted in the Kurung Kumey District of Arunachal
Pradesh, six interesting species were collected which were known only from the
type locality. The present
collection of these species from areas other than the type localities confirms
that they may have a wider distribution in this region. Out of the six species, Dalbergia thomsonii Benth., Larsenianthus assamensis S. Dey, Mood & S. Choudhury and Plectocomia himalayana Griff. are reported for the first time
from the state while Begonia silhetensis (A.DC.) C.B. Clarke, Larsenianthus arunachalensis M. Sabu, Sanoj & T. Rajesh Kumar and Tricarpelema glanduliferum (J. Joseph & R.S. Rao) R.S. Rao show
extended distribution. These
species are provided with the valid name, citation, family name in
parenthesis, followd by the
specimens studied, a short description, phenology data, critical field notes
and photographs for easy identification. The herbarium where the specimens were available are also given in
parenthesis. (CAL: Central National Herbarium; ARUN: Herbarium, Botanical
Survey of India, Arunachal Pradesh Regional Centre).
1. Begonia silhetensis (A.
DC.) C.B. Clarke in Hook, f., Fl. Brit. India 2: 636. 1879; Golding &
Kareg. in Smithsonian Contr. Bot. 60: 233. 1986. Casparya silhetensis A. DC., Prodr. 15(1): 277. 1864. (Begoniaceae)
Specimens
studied: Arunachal Pradesh: Abor Hills, I.H. Burkill 37376 (CAL); Kurung Kumey
District: On way from Sangram to Koloriang, S.S. Dash 31223 (ARUN); NEFA
(Kameng), G.Panigrahi 6029 (CAL).
Succulent
herbs with tuberous, fibrous rootstock. Stem 35–90 cm high,
glabrous. Leaves obliquely ovate-cordate, 16–28 x 13–22 cm,
glabrous, glaucous and whitish beneath, shaggy on both surfaces, base broadly
cordate, margins finely denticulate, often glandular at dentate tips, apex
acute or acuminate, broadly palmately veined with 7–8 further forked
midribs; stipules ovate, 1–1.5 cm long, apex acuminate; petioles
15–50 cm long, glabrous or occasionally covered with whitish hairs, often
purple tinged. Inflorescence in
scapes, 5–12 cm long. Flowers unisexual. Male
flowers: white or pinkish-white; sepals two, oblanceolate or oblong-ovate,
1–1.8 x 0.8–1.5 cm; petals usually two, occasionally 3–10,
cyclic; stamens numerous, yellowish. Female flowers: sepals and petals similar
to male flowers; styles bifid, connate at base. Fruits globose, 1.5–4.5
cm across, glabrous to densely brownish hairy, often variegated.
Flowering
& Fruiting: January–June.
Ecology:
Found in gregarious patches on forest floors, moist and damp grounds of primary
forests, 800–1500 m.
Notes:
After type, this species was first collected by I.H. Burkill from the Abor
Hills of Arunachal Pradesh on 24.xi.1911 and was known only from its type
locality till it was recollected from Kameng District of Arunachal Pradesh on
24.iii.1957 by G. Panigrahi. While
exploring the Kurung Kumey District, the species was again collected and a good
population was found scattered along the primary forest floors.
2. Dalbergia thomsonii Benth.
in J. Linn. Soc. Bot. 4 (Suppl.): 33.1860; Baker in Hook. f., Fl. Brit. India 2: 236. 1876; Sanjappa,
Legumes India 141. 1992. Amerimnon thomsonii (Benth.) Kuntze, Revis. Gen. Pl. 1: 159.
1891. (Leguminosae-Papilionoideae)
Specimens
studied: Arunachal Pradesh: Kurung Kumey District: Kurung River to Yangtey,
S.S. Dash 32834 (ARUN); Lower Subansiri District: Yazali, G.D.Pal 1265 (ARUN);
West Siang District: on way to Kane Wildlife Sanctuary, S.S. Dash 32280 (ARUN).
Large
woody climbers. Stem glabrous; branchlets lenticellate. Leaves 10–15 cm long, petioles
terete; leaflets imparipinnate, oblong-elliptic or elliptic, 2–3.5 x
1–2 cm, glabrous on both surfaces, base cuneate or rounded, margins
entire, apex emarginate; lateral veins 7–8 pairs, prominent beneath;
petiolules 3–4 mm long, terete; stipules 4–5 mm long. Inflorescence in axillary and terminal
panicles, corymbose at first; branches ascending and ultimate becoming scorpioid.
Flowers deciduous; bracts acuminate. Calyx minutely pubescent, unequally 5-lobed; upper 2-lobed, rounded at
apex, connate at base; lower 3-lobed. Petals pinkish-white; standard suborbicular or elliptic-obovate,
7–10 x 5–8 mm, emarginate at apex; wings oblong; keels boat
shaped. Anther filaments unequal, connate
with a sheath at base. Pods
greenish, narrowed at base, strap shaped, 5–10 x 2.5–4 cm,
indehiscent, glabrous. Seed one.
Flowering
& Fruiting: July–January.
Ecology:
Found occasionally in the primary dense forests, 400–1200 m.
Notes:Dalbergia thomsonii Benth. is endemic to Assam, Meghalaya and
Tripura (Kumar & Sane 2003). This species was first collected from Arunachal Pradesh by G.D. Pal from
Yazali of Lower Subansiri District and wrongly identified as Dalbergia assamica Benth. [synonym of Dalbergia lanceolaria L.f. var. assamica (Benth.) Thoth.]. The species was again collected by one
of us (SSD) from subtropical primary forests of Kurung Kumey and West Siang
districts. Dalbergia thomsonii Benth. can be differentiated from the other
climbing species of the genus Dalbergia of Arunachal Pradesh by the presence of
emarginate elliptic leaves, axillary and terminal panicled inflorescence which
are initially corymbose later becoming ascending scorpioid.
3. Larsenianthus arunachalensis M.
Sabu, Sanoj & T. Rajesh Kumar in PhytoKeys 1: 28, fig 4 & Pl. 1D. 2010.(Zingiberaceae)
Specimens
studied: Arunachal Pradesh: Kurung Kumey District: along the Wabia River, on
way to Parlo, S.S. Dash 31721 (ARUN).
Herbs,
1–1.5 m high. Rhizomes c. 1.9cm across, hard, fibrous,
slightly aromatic, inner colour pale brown. Leaves 2–4 per flowering shoot, elliptic-oblong,
35–75 × 11–18 cm, base narrowly attenuate, margins entire,
apex finely acuminate; lateral veins depressed below; basal leaf sheath red,
glabrous; petioles 15–25 cm long, glabrous; ligules lanceolate 6–12
× 2–2.5 cm, glabrous, apex attenuate. Inflorescence terminal on leafy shoots, erect, 25–65
cm long; spikes elliptic, 11–15 x 3–4 cm; floral bracts deep red,
spirally arranged and closely imbricate, orbicular to broadly elliptic,
2–2.7 × 2.5–2.8 cm, coriaceous, glabrous, apex acute;
bracteoles tubular, longer than bracts. Flowers conspicuous, 2–4 per
bract. Calyx tubular, pale red,
white towards base, 1.4–1.6 cm long, glabrous, apex trilobed; floral tube
red, 3.2–3.3 cm long; dorsal lobe reflexed, sparsely pubescent; lateral
lobes glabrous. Lateral staminodes
orbicular to broadly elliptic, pinkish-white; labellum red to creamy yellow
towards base, 20–25 × 2.5–3 mm; fertile stamens red; anthers
creamy-yellow, arching like a fish-hook. Ovary trilocular; stigma white, bulbous, margins ciliate, exserted.
Flowering
& Fruiting: July - September.
Ecology:
Occasionally found in dense and extremely moist primary forests,
1200–1500 m.
Notes:
This species was recently described by Sabu et al. from Lohit District of
Arunachal Pradesh (Kress et al. 2010) and was known only from the type
locality. While surveying the Kurung Kumey District, the species was collected
by one of us (SSD) from a single locality where c. 150 adult plants were
growing. The occurrence of this
species in Kurung Kumey District shows that the species might have a wider
distribution in the state. It is
interesting to note that the specimens collected from Kurung Kumey District
differ from the protologue by its complete nature of glabrousness. Studies on the herbarium specimens as
well as live plants in the field, could not confirm the hairy nature of leaf
ligules, pubescent nature of the leaf lamina with silvery hair, twisting condition
of the leaf apex and pubescent nature of the floral bract as mentioned in the
protologue.
4. Larsenianthus assamensis S. Dey, Mood & S. Choudhury in PhytoKeys 1: 26, fig.3 & Pl. 1C. 2010.(Zingiberaceae)
Specimens
studied: Arunachal Pradesh: West Siang District: on way to Kane Wildlife
Sanctuary, S.S. Dash 32218 (ARUN).
Rhizomatous
herbs, 60–80 cm high.Leaves oblong-lanceolate or elliptic-lanceolate, 20–35 × 5–7 cm, glabrous
above, glaucous beneath, base narrowed to a leaf sheath, margins entire, apex
finely acuminate; leaf sheaths 5–11 cm long, drying brown, whitish
inside; ligules bilobed. Inflorescence terminal, usually on a reflexed peduncle, erect, 7–9
x 3–8 cm, glabrous; involucral bracts deep red, 3–4 x 0.7–1
cm, acuminate at apex; floral bracts overlapping, closely clasping to each
other, 2–3 x 0.8–1.3 cm, conspicuously veined. Flowers white, 1-3
per bract. Calyx tubular. Corolla lobes linear-lanceolate; lobes
conspicuous. Staminodes reddish, ovate, with a reflexed labellum of 2–2.5
cm long; fertile stamens whitish, light orange outside arched at base, oblong.
Ovary trilobed.
Flowering
& Fruiting: July–September.
Ecology
: Occasionally found in the primary dense forests, 300–700
m.
Notes:
This species was recently described from Barail Wildlife Sanctuary, Cachar
District, Assam by Dey et al. and was known only from two locations in
the sanctuary (Kress et al. 2010). The present collection from the Kane
Wildlife Sanctuary (West Siang District) establishes northern extension of the
species and its first record for the state of Arunachal Pradesh. During the
survey, only 10–15 plants were observed in the field.
5. Plectocomia himalayana Griff.
in Calcutta J . Nat. Hist. 5: 100.1845; Karthik et al., Fl. Ind. Enum. Monocot. 21. 1989;
Govaerts & J. Dransf., World Checklist Palms 180. 2005. (Arecaceae)
Specimens
studied: Arunachal Pradesh: Kurung Kumey District: Miri to Yangtey, S.S. Dash
31341(ARUN).
Scandent
shrubs. Stems up to 20m long, ascending. Leaf sheaths tomentose, densely spiny;
spines straight, arranged in wavy manner, oblique at mouth. Petioles very
short, often clasping to stem. Leaves 2–3.5 m long; pinnae linear-lanceolate, narrowed to a long
filiform cirrate apex; rachis flattened, tomentose, lower part sometimes spiny,
upper part heavily armed with recurved spines (grapnels). Male rachis zigzag; bracteoles minute;
inflorescences axillary; peduncles drooping, covered with densely overlapping
floral bracts broadly ovate or rhombic, 4–5 cm long, apex acuminate;
calyx tubular, finely tomentose outside, apex acuminate. Fruits globose,
spherical, reddish-brown on maturity.
Flowering
& Fruiting: August–March.
Ecology:
Common in dense subtropical forests, 500–2000 m.
Notes:
This species is distributed from Nepal to China (Yunnan). In India it was known to occur in
Sikkim. The present collection
from Kurung Kumey District forms the basis for the first report of its
distribution in Arunachal Pradesh. Vegetatively, the species is easily confused with the scandent species
of Calamus in wild, but can be differentiated by the
presence of sharp spines on wavy lamellae, long filiform leaf tips, drooping
inflorescence and rachilla often hidden by broad bracts. Traditionally the pith of this species
is used as fodder and the stem fiber is used for making houses and baskets by
the Nishi tribe.
6. Tricarpelema glanduliferum (J.
Joseph & R.S. Rao) R.S. Rao in J. Indian Bot. Soc. 59 (Suppl.): II(III).
1980; Karthik. et al. Fl. Ind. Enum. Monocot. 31. 1989; Faden in Novon 17: 167.
2007. Aneilema glanduliferum J. Joseph & R.S. Rao in J. Indian Bot.
Soc. 47: 367. 1969. (Commelinaceae)
Specimens
studied: Arunachal Pradesh: Kurung Kumey District: near Palin, S.S. Dash 31334
(ARUN).
Herbs.
Stems up to 85cm high, puberulous or glabrous. Leaves lanceolate, 11–17 x
1–5 cm, upper surface papillose-hispid, hispid only on veins beneath,
finely acuminate at apex, hispid-ciliate at margins, narrowed to very short
petiole-like base; sheaths widely cylindric, 2.2–3 cm long; upper leaves
almost overlapping. Inflorescence 5–17.5 cm long, densely
glandular-pubescent, terminal; bracteoles leaving scars; flowers borne near
ends of branches; pedicels 1–1.5 cm long. Flowers pale mauve to bright
blue. Sepals oblong-elliptic, margins scarious, apex hooded, 4–5 x 3 mm,
glandular-pubescent. Petals obovate, rounded, c. 6 x 5 mm. Ovary narrowly ellipsoid, c. 3 x l mm, tapering upwards into style, glabrous; style c. 9mm
long, filiform, twisted at apex. Fruiting branch stout, upward curving, each
bearing single capsule. Capsule segments narrowly oblanceolate.
Flowering
& Fruiting: July–October.
Ecology:
Scattered along river banks or stream sides, 700–1800 m.
Notes:Tricarpelema glanduliferum (J. Joseph & R.S. Rao) R.S. Rao is
known to occur in India (Arunachal Pradesh) and Vietnam. This species was described from Kameng
District of Arunachal Pradesh. Tricarpelema
glanduliferum is
very similar to Tricarpelema giganteum (Hassk.) H. Hara which occurs commonly in
Eastern Himalaya. However, the
former species can be differentiated from the latter by the presence of
multicellular glandular hairs in inflorescence and pedicels. Due to their close morphological
similarity, either of the species is often overlooked by the collectors, unless
both the species are in flowering condition. The present collection of this rare species made on 08
September 2009 from Arunachal Pradesh after a lapse of 46 years after type
collection from an area other than the type locality also confirms occurrence
of this species in India.
REFERENCES
Biswas, K.P. (1966). Plants of
Darjeeling and the Sikkim Himalayas.Government Press, Calcutta, 540pp,
Hajra, P.K. & V. Mudgal (1997). Diversity in Hotspots - An Overview.
Botanical Survey of India, Calcutta, 1-12pp
Kress, W.J., J.D. Mood, M. Sabu, L.M.
Prince, S. Dey & E. Sanoj (2010). Larsenianthus, a new Asian genus of Gingers
(Zingiberaceae) with four species. PhytoKeys 1: 15–32.
Kumar, S. & P.V. Sane (2003). Legumes of South Asia. Royal Botanic Gardens, Kew, p.176.
Rodger, W.A., H.S. Panwar & V.B.
Mathur (2000).Biogeographical Classification of India in Wildlife Protected Area Network in
India: A Review (Executive Summary). Wildlife Institute of India, Dehra Dun,
49pp.
Takhtajan, A.
(1969). Flowering Plants, Origin and Dispersal. Edinburgh: Oliver & Boyd, 310pp.