Diversity and distribution of the genus Rhynchotechum Blume (Gesneriaceae) in Arunachal Pradesh, India

Abstract

A taxonomic investigation on the genus Rhynchotechum Blume (Gesneriaceae) in the state of Arunachal Pradesh, India was carried out during 2018-2022. The present revisionary studies have reported 7 taxa from Arunachal Pradesh. All the recorded species are enumerated here with taxonomic keys and notes based on morphological characters of living plants, along with the distributional ranges and colored photographs.

Full text

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RESEARCH ARTICLE
Diversity and distribution of the genus
Rhynchotechum Blume (Gesneriaceae) in Arunachal
Pradesh, India
Momang Taram and Hui Tag*
Plant Systematics and Ethnobotanical Research Laboratory, Department of Botany, Rajiv Gandhi University, Rono Hills, Doimukh -791112,
Arunachal Pradesh, India
Corresponding author email: hui.tag@rgu.ac.in; momang.taram@rgu.ac.in
Article No.: MTJBR09; Received: 20.04.2022; Reviewed: 18.05.2022; Revised: 15.06.2022; Accepted and Published: 30.06.2022
Doi: https://doi.org/10.5281/zenodo.8369779
Abstract
A taxonomic investigation on the genus Rhynchotechum Blume (Gesneriaceae) in the state of Arunachal Pradesh, India was carried out during
2018-2022. The present revisionary studies have reported 7 taxa from Arunachal Pradesh. All the recorded species are enumerated he re with
taxonomic keys and notes based on morphological characters of living plants, along with the distributional ranges and colored photographs.
Keywords: Rhynchotechum, Gesneriaceae, Diversity, Arunachal Pradesh, India
1. Introduction
State of Arunachal Pradesh is reported as richest botanical province
in India, which harbors about 50% of the India’s flora, and 4% of them
are reported to be endemic to the region (Taram et al., 2020c; Borah
et al., 2019). Wide range of agro-climatic conditions and altitudinal
variations found in the region confers ideal habitat for the
proliferation of phyto-diversity in different vegetation types found in
the state of Arunachal Pradesh (Taram et al., 2020b). Arunachal
Pradesh harbors highest number of Gesneriad members among the
states of North Eastern India. Gesneriaceae is one of the flowering
plant families in the order Lamiales which comprises around 3400
species and roughly a one-third of its total species are distributed in
the New world and two-third in Old world in tropical and subtropical
moist forest (Taram et al., 2021). In India, Gesneriaceae shows
maximum diversity of genera in Northeastern Region of India while
maximum species diversity have been reported from states of Assam
and Arunachal Pradesh (Roy 2017).
The genus Rhynchotechum Blume is an important genus of the
Gesneriaceae, which belonging to sub-family Didymocarpoideae,
tribe Trichosporeae and sub-tribe Leptoboeinae (Weber et al., 2013;
Moller et al., 2017). Th e genus was described by Blume in 1826, and
it comprises a group of understorey subshrubs, cymose inflorescences
with relatively small flowers (white to pink) with short corolla tube
and indehiscent white berries. They are found to be distributed in
tropical and subtropical Asia from India to China, north to the
Ryukyus in Japan, south through the Philippines and the Malay
Peninsula to Sumatra and east to Papua New Guinea (Anderson and
Middleton, 2013). Rhynchotechum Blume has been revised recently
by Anderson and Middleton (2013) who recognized a total of 16
species, excluding the recently described species: R. nirijuliense
Taram & D. Borah (Taram and Borah, 2020) and R. lalashanense S.S.
Ying vide POWO (2020); https://padme.rbge.org.uk/GRC).
In India, a total of ten species of Rhynchotechum have been reported
which include: R. alternifolium C.B.Clarke, R. calycinum C.B.Clarke,
R. ellipticum (Wall. ex D.Dietr.) A.DC., R. gracile B.M.Anderson, R.
hookeri (C.B. Clarke) B.M. Anderson, R. nirijuliense Taram & D.
Borah, R. obovatum (Griff.) B.L.Burtt, R. parviflorum Blume, R.
permolle (Nees) B.L.Burtt and R. vestitum Wall. ex C.B.Clarke
(Anderson and Middleton, 2013; Sinha and Datta, 2016; Möller et al.,
2017; Roy, 2017; Roy et al., 2019; Taram et al., 2020; Taram & Borah
2020) from which nine species (with the exception of R. permolle)
are distributed in North East India while R. nirijuliense and R.
calycinum are reported to be endemic to Northeast India. Among the
ten species, eight species of Rhynchotechum have been reported from
Arunachal Pradesh (Anderson and Middleton, 2013; Sinha and
Dutta, 2016; Roy et a l., 2019; Taram and Borah, 2020; Taram et al.,
2020a) but the present field investigation has recorded seven
Rhynchotechum species with immense foliar and floral diversity
found in the state of Arunachal Pradesh.
Although Gesneriaceae is economically less important but many
Gesneriads are reported as ethno-botanically significant for some
tribal communities (Roy 2017). Taram et al (2021) have reported 21
ethno-botanically significant Gesneriads of Arunachal Pradesh which
includes the seven Rhynchotechum species. The presen t field
investigation has reported taxonomic diversity of Rhynchotechum
species of Arunachal Himalaya along with their current taxonomic
status, distribution and endemism range.
2. Materials and methods
The present taxonomic revisionary study was carried out during the
year 2018–2022 along different altitudinal ranges in the state of
Arunachal Pradesh. Extensive field surveys were conducted in
different districts of Arunachal Pradesh during different seasons of
the year. Flowering and fruiting seasons were recorded and flowering
twigs were collected from the field and photographed using a digital
camera (Nikon COOLPIX B600, Nikon India Pvt. Ltd). GPS
coordinates were recorded using Garmin GPS (Etrex 10 device, Asim
Navigation India Pvt. Ltd). The specimens collected from each field
visits were processed using standard herbarium methods (Jain and
Rao, 1977) and voucher specimens were deposited in ARUN, ASSAM,
CAL, E and Herbarium of Arunachal University (RGUH/HAU),
Department of Botany, Rajiv Gandhi University, Itanagar, Arunachal
Pradesh for future reference. Morphological observations were made
ISSN: 2394-4315 (Print)
ISSN: 2582-2276 (Online)
Journal of Bioresources 9 (1): 48–53, January – June 2022
JOURNAL OF BIORESOURCES
journal webpage: http://jbr.rgu.ac.in
©JBR2022 Published by Centre with Potential for Excellence in Biodiversity, Rajiv Gandhi University, Rono Hills, Doimukh-791112, Itanagar, Arunachal Pradesh,
India. Visit: http://jbr.rgu.ac.in; Email: editorjbiocpebrgu2014@gmail.com; Phone: +91-8131871644

49
on both fresh and dried specimens. Morphological characters were
compared with those reported in the literatures: Wang et al (1998),
Giri et al (2008), Anderson and Middleton (2013), Sinha and Dutta
(2016), Roy (2017), Roy et al. (2019), Taram and Borah 2020, Taram
et al. (2020a) and digital images of type specimens housed in K, E,
PE, ASSAM, ARUN and CAL (http://apps.kew.org>herbcat;
https://www.rbge.org.uk; http://pe.incas.ac.cn>).
3. Results
3.1. Taxonomic treatment
Rhynchotechum Blume, Bijdr. Fl. Ned. Ind. 775. 18 26. Synonym: Isanthera Nees. In Trans. Linn. Soc. London xvii: 82. 1834; Corysanthera
[Wall ex] Endl. Gen. Pl.719. 1839; Cheilosandra [Griff ex] Lindley, veg. Kingd. 672. 1847; Chiliandra Griff. Notulae, iv, 150. 1854 et Ic. Pl. Asiat.
T 438. 1854. Type: Rhynchotechum parviflorum Blume.
Key to the Rhynchotechum species of Arunac hal Pradesh
1a. Inflorescence often with solitary peduncles from leaf axils; leaves whorl of 3 or alternate…………………………………………………2
1b. Inflorescence with a reduced/absent peduncle so that the branches appear fascicled from leaf axils; leaves opposite………….3
2a. Leaves and peduncles opposite or whorled; leaves abaxially sub-glabrous between the veins……………………………………………….….R. obovatum
2b. Leaves and peduncles alternate; leaves abaxially woolly between the veins…………………………… ………………..………………………..……R. alternifolium
3a. Plants hispid, hairs stiff; calyx lobes distinctly caudate…………………………………………………………………………………………..……… ….….R. vestitum
3b. Plants woolly pubescent, sub-glabrous at maturity, hairs not stiff;
calyx lobes triangular to linear acuminate, only rarely somewhat caudate……………………… …………………………….……………………….4
4a. Compact Inflorescences; calyx segments glabrous, fruits globose………………………………………………………..……………………………….…R. calycinum
4b. Inflorescence and calyx segments scabrous or villous/sericeous, fruit ovoid to ellipsoid…………………………………………………… 5
5a. Inflorescence spreading, pedicels and calyx lobes often scabrous, the hairs conspicuously multicellular; ovary glabrous …………….R. ellipticum
5b. Inflorescence pendulous, pedicels and calyx lobes sericeous or sub-glabrous; ovary glabrous to short pubescent………………..6
6a. Lateral veins of lamina more than 30, berry ovoid………………….....….……………………………………………………………………………………….R. nirijuliense
6b. Lateral veins of lamina less than 30; berry ellipsoid or broadly ovoid.…………………..………………………………………………………………….R. parviflorum
Figure 1. Distribution of Rhynchotechum species in Arunachal Pradesh.
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Figure 2. A-R. alternifolium, B- R. calycinum, C- R. ellipticum, D- R. nirijuliense, E- R. obovatum, F- R. vestitum, G- R. parviflorum
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(3.1.1) Rhynchotechum alternifolium C.B.Clarke in A.DC. &
C.DC., Monogr. Phan. 5(1): 198. 1883; C.B.Clarke in Hook.f., Fl. Bri t.
India 4: 374 1884; Sinha & Dutta, Nelumbo 58:39.2016.
Synonym: None
Type: India, Upper Assam, by lake Brahmakoondo [Brahmakund],
Griffith 3850 (K).
Stems glabrescent. Leaves alternate to sub-opposite. Inflorescence
spreading, 5–20 cm long, 4–5-branched; peduncle 2.5–11.5 cm long;
bracts linear to triangular. Calyx lobes oblong to ovate-elliptic,
glabrous to sparsely sericeous. Corolla white, exterior glabrous; upper
lip with darker patch, 3–3.5 × 5 mm, apices obtuse; lower lip 4.5–5 ×
7 mm; lower lobes 2.25–2.5 × 2–2.5 mm, apices rounded to obtuse;
tube 1.5 mm long. Stamens inserted near the base of the corolla tube;
filaments c.1 mm long. Ovary slightly puberulent; style 5–7 mm long;
stigma apex globose to truncate. Fruit ovoid, glabrous.
Flowering and fruiting: February, August and November.
Habitat and ecology: Growing in evergreen and mixed forests at
an elevation from 350 – 800 m msl in association with
Rhynchotechum obovatum, Boeica fulva, Begonia burkilii, Begonia
dicrassine, Thladiantha species, Polygala arillata, Urtica species
and many more.
Distribution: India (Arunachal Pradesh) and Myanmar
Specimen examined: India, Arunachal Pradesh, Changlang,
Namdhapa National Park, 450 m msl, 12 August 2021
(3.1.2). Rhynchotechum calycinum C.B.Clarke in A.DC. &
C.DC., Monogr. Phan. 5(1): 199. 1883; C.B. Clarke in Hook.f., Fl. Brit.
India 4: 374. 1884; Burkill, Rec. Bot. Surv. India 10: 330. 1925;
G.D.Pal & Thoth., Bull. Bot. Surv. India 30: 173. 1988; Giri et al., Mat.
Fl. Arunachal Pradesh 2: 234. 2008; Kumar, A., Floristic Diversity of
Arunachal Pradesh (Upper Subansiri District) 343. 2013; G. D. Pal,
Fl. Lower Subansiri District, Arunachal Pradesh 2: 176. 2013; Sinha
and Datta, Nelumbo 58: 40. 2016
Synonym: None
Type: India, Upper Assam, on the banks of the river Soondra,
Unknown s.n. (holo K).
Stem glabrous. Lea ves opposite; petiole sessile. Inflorescence
axillary, pendulous compact, 1 - 4 cyme per axil, 2-4 -branched;
peduncle 2-4 cm long, glabrous; bracts elliptic to lanceolate, acute,
sub entire; first bract 1.8–2.5 cm × 0.7 - 1 cm, second bract 1.3 -2 cm
× 0.4-0.8 cm; pedicels sub-glabrous. Calyx creamy white, lobes
triangular or oblong to linear, apices acute to obtuse, 0.5–0.8× 0.2-
0.3 cm, glabrous, margin entire. Corolla white, exterior glabrous.
Stamens yellow inserted near the base of the corolla tube,
didynamous; filaments 1–2 mm long. Disk annular. Ovary glabrous;
style 0.3 - 0.4 cm long. Fruit ellipsoid to globose, 2.5–2.75 × 2–2.25
mm, glabrous.
Flowering and fruiting: June - August.
Distribution: Endemic to Northeast India (Arunachal Pradesh,
Assam)
Habitat and ecology: Growing on the margins of primary forest,
often in moist and shady conditions, along streams side or road sides
at an elevation from 300 -700 m msl. It grows with an association
with Musa species, Begonia burkilli, Strobilanthus species,
Elatostemma species, Urtica species, Calocasia species, Ferns,
Alpinia species, Amomum species etc.
Specimen examined: India, Arunachal Pradesh, Lower Siang
district, on the way to Koyu, 530 m amsl, 12 July 2019, Momang
Taram (982, 983) (ARUN, RGUH/HAU)
(3.1.3). Rhynchotechum ellipticum (Wall. ex D.Dietr.) A.DC. in
DC., Prodr. 9:285.1845; C.B.Clarke, Commelyn. Cyrtandr. Bengal.
131, pl. 41. 1874; in A.DC. & C.DC., Monogr. Phan. 5(1): 196.1883; in
Hook.f., Fl. Brit. India 4: 373. 1884; Kumar A., Floristic Diversity of
Arunachal Pradesh (Upper Subansiri District) 343. 2013; G. D. Pal,
Fl. Lower Subansiri District, Arunachal Pradesh 2:178. 2013; Sinha
and Datta, Nelumbo 58: 39. 2016
Synonym: Chiliandra obovata Griff. Not Pl. Asiat 4: 150. 1854.
Corysanthera e lliptica Wall. ex D. Dietr Syn. Pl. 3: 582. 1843.
Rhynchotechum latifolius Hook. f., et Thomson ex C. B. Clarke
Commelyn. Cyrtandr. Bengal. t. 94.1874.
Type: Mts Sylhet, F. de Silva, W. Gomez & H. Bruce in Wallich 6411
(K)
Stems 60–180 cm tall. Leaves opposite; petiole 1–4 cm long; lamina
elliptic to narrowly elliptic. Inflorescence spreading, pink, 1.2–13.5
cm long, 2–6 branched; peduncle reduced ; axes short yellow-rusty
villous becoming scabrous to sub-glabrous higher up; bracts linear to
triangular, first bract 3–6 mm long, second bract 3–5 mm long;
pedicels, scabrous to sub-glabrous. Calyx pink to pale pink, lobes
triangular to linear acuminate with apices rounded, 3–4.5 × c.1–1.5
mm. Corolla red-purple, exterior scabrous with glandular hairs.
Stamens inserted near the base of the corolla tube; filaments c.1 mm
long; anthers purple, c.1–1.5 mm diameter, slightly puberulent. Ovary
1–1.5 × 1–1.75 mm, glabrous to rarely puberulent with glandular
hairs; style 6–7 mm long; stigma apex globose to truncate. Fruit
broadly ovoid, 3–4.5 × 3–4. 5 mm, glabrous.
Flowering & Fruiting: July to November
Distribution: India, Bhutan, Bangladesh, Nepal and Burma.
Habitat and ecology: Growing in primary and secondary forests,
typically in shady and moist conditions along road side, stream side
and on rocky places.
Specimen examined: India, Arunachal Pradesh, Papum Pare
district, Jote road, 19 September 2019, Momang Taram 1020
(ARUN); India, Arunachal Pradesh, Papum Pare district, 430 m amsl,
19 September 2018, Momang Taram 813 (RGUH/HAU)
(3.1.4). Rhynchotechum nirijuliense Taram & D. Borah in
Gardens' Bulletin Singapore 72(1): 125–129. 2020. Type: India,
Arunachal Pradesh, Papum Pare district, Nirjuli, Bage Hills, tropical
bamboo forest, 27°7'19"N, 93°43'56"E, 166 m, 1 May 2019, M. Taram
& D. Borah 0157 (holotype CAL; isotypes ASSAM, ARUN, E).
Stems to 2 m tall. Leaves opposite; almost sessile, petiole if present
0.5–1.2 cm long. Inflorescence axillary, pendulous; peduncle reduced
or absent, branches 4–6 from each node, axes densely villous; bracts
ovate to ovate lanceolate, navicular, undulate, deeply grooved along
the midvein, paired, each at the axil of the first branches, 10–12 × 4–
6 mm; bracteoles paired, one per branch, pale pink, ovate, entire,
membranous, midvein prominent, 1–1.2 × 0.8–1 cm; pedicels 0.3–
1.5 cm long, silky villous. Calyx divided to near the base, tube 1–2mm
long, lobes ovate lanceolate, with broadly acuminate apices, 7–10 ×
1.8–2.2 mm, equal to or longer than the corolla, villous outside,
glabrous inside. Corolla pink, exterior glabrous; tube 2–3 mm long.
Stamens inserted near the base of the corolla tube; filaments c. 1 mm
long; anthers c. 1.5 mm diameter, glabrous; staminode
inconspicuous. Ovary ovoid, 1–1.5 × 1–1.2 mm, glabrous; Fruits
ovoid, 1.2–1.5 × 0.7–0.9 cm, glabrous.
Flowering and fruiting: flowers from April to May, fruiting is from
May onwards.
Distribution: India (Arunachal Pradesh).
Habitat and ecology: It occurs in damp and shady areas alongside
streams and grows in association with Begonia aborensis, Impatiens
laevigata, Impatiens ma rianae, Impatie ns porrecta, Litsea
lancifolia, Pseuderanthemum latifolium, Strobilanthes secunda etc.
Specimen examined: India, Arunachal Pradesh, Papum Pare
district, Nirijuli, Bage Hills, 27°7'19"N, 93°43'56"E, 166 m, 1 May
2019, M. Taram & D. Borah 0157.
(3.1.5). Rhynchotechum obovatum (Griff.) B.L.Burtt, Notes
Roy. Bot. Gard. Edinburgh 24: 38. 1962; Chun (ed.), Fl. Hainan. 3:
528.1974.; C.B.Clarke in A.DC. & C.DC., Monogr. Phan. 5(1): 198.
1883; in Hook.f., Fl. Brit. India 4: 374. 1884.
Synonym: Chiliandra obovata Griff., Not. Pl. Asiat. 4: 150.1854
Type: Griff., Icon. Pl. Asiat. 4: pl. 438 (1854) (K [K000249997]
Stems 60–100 (–120) cm tall. Leaves whorled (of 3), rarely opposite
to alternate lower down; petiole 1–6 cm long. Inflorescence axillary,
spreading, 5–11 cm long, up to 4 branched, branches purple tinged;
peduncle 2.5–5.5 cm long, axes short yellow-rusty villous; bracts
linear subulate; pedicels 0.3–1 cm. Calyx villous(outside), glabrous
51
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Momang & Tag, 2022

49
(inside), green-pale pink, 0.4–0.5 x 0.10–0.12 cm,lobes triangular
with rounded or slightly caudate apices; corolla white or pale pink,
glabrous to slightly puberulent exteriorly; tube 1.5–2 mm long. Ovary
1.5–2.5 x 1–1.75 mm, glabrous to rarely puberulent, with glandular
hairs; style 5.5–7.5 mm long; stigma apex globose/ rounded to
truncate. Fruit ovoid.
Flowering and fruiting: July - September.
Distribution: Bangladesh, India, Burma, Thailand, Vietnam, Laos,
Cambodia and China.
Habitat and ecology: Growing in wet to dry primary and secondary
evergreen forests, sometimes disturbed areas or on gentle to steep
slopes, at 197–2120 m.
Specimen examined: India, Arunachal Pradesh, Lower Subansiri
District, Potin, 23 July 2019, Momang Taram 1020 (ARUN,
RGUH/HAU)
(3.1.6). Rhynchotechum parviflorum Blume, Bijdr. Fl. Ned.
Ind. 775. 1826; C.B.Clarke in A.DC. & C.DC., Monogr. Phan. 5(1): 195.
1883 in Hook.f., Fl. Brit. India 4: 373. 1884; Vietnam 3(1): 25. 199 3;
Taram et al., in JOTT 12(1): 15208–15211. 2020
Synonym: Cyrtandra microcarpa C.B.Clarke in A.L.P.P.de
Candolle & A.C.P.de Candolle, Monogr. Phan. 5: 195.1883.
Type: Java, Seribu mountains, Blume s.n. [0834014]
Stems 20 –180 cm tall. Leaves opposite, rarely sub-opposite; petiole
1.7– 5 cm long. Inflorescence axillary, pendulous, 1.3–6 cm long, 2–
4-branched; peduncle reduced/absent; axes rusty-yellow villous to
sub-glabrous, rarely with glandular hairs present; bracts linear to
triangular or subulate; pedicels 0.1–1.1 cm long, yellow-rusty villous.
Calyx purplish red or green to pinkish brown, lobes triangular with
apices rounded, rarely somewhat caudate, 0.2– 0.4 cm × 0.75–1.5
mm, yellow-rusty villous to sub-glabrous or scabrous with glandular
hairs. Corolla white to pale purple, exterior glabrous to slightly
puberulent. Stamens inserted at 0.5–0.75 mm above the base of the
corolla tube. Ovary 0.75–1.25 × 0.75–1.5 mm, short pubescent to
puberulent; style white, 1.5–3.25 mm long; stigma white, apex
truncate to globose. Fruit widely ellipsoid or widely ovoid, 0.3–0.4 ×
0. 2–0.5 cm, glabrous.
Flowering and fruiting: recorded in all months.
Distribution: India, Burma, Thailand, Vietnam, China, Sumatra,
Kalimantan, Sulawesi, Indonesian New Guinea, Papua New Guinea
and the Philippines.
Habitat and ecology: It usually prefers cliffs near perennial
streams in primary forests as well as in secondary forests and damp
groves near roadsides at an elevation from 300-800 m msl. It grows
in associations with Diplazium esculentum, Henckelia pumila,
Boeica clarkei, Rhynchotechum vestitum, Pilea insolens, Pilea
umbrosa, Mycetia mukerjiana, Cyclosorus parasiticus,
Strobilanthes hamiltoniana, Justicia sp. Etc.
Taxonomic note: Rhynchotechum hookeri can be recognised by its
fairly compact and sub-glabrous inflorescences. It differs from R.
parviflorum in its more entire leaves, its smaller inflorescence, its
less puberulent ovary, and its typically longer style (Anderson and
Middleton 2013). But these characteristics mentioned for R. hookeri
has been observed in the R. parviflorum populations in Arunachal
Pradesh. Occurrence of R. hookeri is doubtful in Arunachal Pradesh.
(3.1.7). Rhynchotechum vestitum (Griff.) Wall. ex C.B.Clarke,
Commelyn. Cyrtandr. Bengal. 132, pl. 92. 1874; C.B.Clarke in A.DC.
& C.DC., Monogr. Phan. 5(1):197. 1883; in Hook.f., Fl. Brit. India 4:
373. 1884; Kanjilal et al. in Fl. of Assam 3:399.1939; Giri et. al., Mat.
Fl. Arunachal Pradesh 2: 234. 2008; A. Mukherjee et. al., Pleione 2
(2): 160. 2008; Kumar, A., Floristic Diversity of Arunachal Pradesh
(Upper Subansiri District) 343. 2013; G. D. Pal, Fl. Lower Subansiri
District, Arunachal Pradesh 2: 179. 2013; Sinha and Datta, Nelumbo
58: 41. 2016.
Synonym: Corisanthera vestita Griffith, Itin. Notes 124. 1848.
Type: Bhutan, 3300 ft, Griffith 426 [ K000249996]
Stems 60 –180 cm tall. Leaves opposite; petio le 2–7 cm long; blade
appressed hispid. Inflorescence appressed axillary, 2 - 4 cymes per
axil, 1.2– 6 cm long, 2–4-branched; peduncle 0.5 – 1.5 cm long (rarely
reduced; bracts triangular to linear; pedicels 0.4–1.5 cm long, densely
long yellow to pink hispid. Calyx whitish to greenish, lobes triangular
with apices caudate, 0.4–0.8 cm × 0.2-0.4 cm, densely long hispid.
Corolla pink to white, glabrous both sides; tube 0.1–0.2 cm long.
Stamens inserted at c. 0.1 cm above the base of the corolla tube,
slightly didynamous. Ovary 0.1–0.2 cm × 0.1–0.2 cm, slightly
puberulent with or without glandular hairs; style 0.2–0.4 cm long;
stigma apex truncate to globose. Fruit white ovoid to widely ovoid.
Flowering and fruiting: March - September.
Distribution: India, Bhutan, Bangladesh, China, Vietnam, Sumatra
and Java.
Habitat and ecology: Growing in rainforests, so metimes
disturbed, in damp and shady conditions, in loam on granite and
limestone, sometimes in ravines, at 450–1220 m.
Specimen examined: India, Arunachal Pradesh, Upper Subansiri
District, Daporijo, 27 July 2019, Momang Taram 1025 (ARUN)
4. Discussion
India has the highest number of Rhynchotechum species (10 spp.) in
the world, of which the distribution of 80% (8 spp.) of the species are
restricted to Northeastern region of India. R. calycinum and R.
nirijuliense are narrowly endemic to North East India. The number
of Rhynchotechum species reported from Arunachal Pradesh in
present studies is much higher than Nepal, Sri Lanka, Japan,
Cambodia, Malaysia, Papua New Gunia and Sri Lanka with 1 species
each; Bhutan, Loas, Philippines and Thailand with 2 species each;
Hongkong with 3 species; Bangladesh and Taiwan with 4 species
each; Indonesia and Vietnam with 5 species each and China with 6
species. However, the number of species in Arunachal Pradesh
(excluding R. hookeri) is equal to Myanmar (7 species each) (Vide
GRC rbge). R. ellipticum, R. vestitum and R. parviflorum are
abundantly distributed in primary and secondary forest along the
stream sides and roadsides while R. calycinum, R. alternifolium, R.
nirijuliense and R. obovatum have been reported to have narrow
range of geographical area highly vulnerable to reduction of present
population size due to habitat destruction. Therefore, natural habitat
conservation and protection is necessary to conserve these rare
Rhynchotechum species in Arunachal Pradesh.
5. Conclusion
The present field investigation has recorded seven species of
Rhynchotechum from Arunachal Pradesh (India) and all the reported
species are ethnobotanically significant to the tribal communities
such as Adi, Galo, Tagin, Nyishi and Lisu. Rhynchotechum species are
locally called as Joko/Jok (Nyshi and Galo), Joku (Tagin) and
Byongkot/Jongkot (Adi). These species are used in different ways:
tender shoot of R. obovatum and R. alternifolium is served as
vegetable, young leaves of R. ellipticum, R. parviflorum and R.
nirijuliense are consumed as addictives, fruit of R. vestitum is eaten
raw and leaves fermented with soyabean, and twig of R. ellipticum
and R. parviflorum are used in local rituals specifically perform
during funeral.
Acknowledgement
The authors are thankful to the Rajiv Gandhi University, Rono Hills,
Doimukh, Arunachal Pradesh, India for providing laboratory and
logistic facilities to carry out the PhD research work on Gesneriaceae
flora of Arunachal Pradesh. The authors are deeply thankful to Prof.
A.P. Das and Dr. Jintu Sharma for their constructive comments on
nomenclatures and inputs.
Author’s contributions
First author (MT) conducted field and literature survey, developed
first of the manuscript. Second author (HT) conceptualized the
research, literature studies, language editing and finalized the
manuscript.
Conflict of interests
Authors have no conflict of interests
References
Anderson BM an d Middleton D J. 2013. A Revision of Rh ynchotechum Blume
(Gesneriaceae). Edinburgh Journal of Botany 70 (1):121-176.
Blume CL. 1826. Bijdragen tot de flora van Nederlandsch Indie¨, Batavia: Ter Lands
Drukkerij. Pp. 759, 775–776.
52
Momang & Tag, 2022
Journal of Bioresources 9 (1): 48–53

50
Borah D, Das AP, Tangjang S and Wangpan T. 2019. Flowering Plant Diversity in the Alpine
Regions of Eastern Himalaya. In: Jayanta KP, Gitishree D, Sanjeet K, Hrudayanath T (Eds.)
Ethnopharmacology and Biodiversity of Medicinal Plants. Apple Academic Press, Palm
Bay, Florida, USA. DOI: 10.1201/9780429398193-8.
Choudhary RK, Srivastava RC, Das AK and Lee J. 2012. Floristic diversity assessment and
vegetation analysis of Upper Siang District of Eastern Himalaya in North East India. Korean
Journal of Plant Taxonomy 42(3): 222-246.
Clarke CB. 1883. Cyrtandreae. In: De Candolle, A. a nd D e Candolle, C. (eds)
Monographiaephanerogamarum, 5:1–303, Paris: Masson.
Clarke CB. 1884. Gesneriaceae. In: J.D. Hooker, Flora of British India Vol. 4, pp. 336 – 375.
L. Reeve & Co., London.
Giri GS, Pramantik A and Chowdhery HJ. 2008. Materials for the flora of Arunachal Pradesh.
Botanical Survey of India, Kolkata, India.
Jain SK and Rao RR . 1977. A hand book of fie ld and Herbarium Methods. Today and
Tomorrow`s Printer and Publishers, New Delhi.
Möller M, Nampy S, Janeesha AP and Weber A. 2017 . The Gesn eriaceae of India:
Consequences of updated generic concepts and new family classification. Rheedea 27 (1):23–
41.
POWO. 2020. Plants of the World Online. Royal B otanic Gardens, Kew.
http://www.plantsoftheworldonline.org
Roy S, Paul TK and Mukherjee SK. 2019. Taxonomic studies of the genus Rhynchotechum of
Indian part of Eastern Himalaya, pp. 145 – 155. In: Agnihotri P and Khuraijam JS (Eds.)
Angiosperm Systematics: Recent Tren ds and Emerging Issues. M/S Bishen Singh
Mahendra Pal Singh, Dehradun, India.
Roy S. 2017. Taxonomic studies of t he family Gesneriaceae of Indian part of Eastern
Himalaya. A Ph.D thesis. University of Kalyani, Kalyani, India.
http://hdl.handle.net/10603/195852
Sinha BK and Datta S. 2016. Taxonomic account on the family Gesneriaceae in Northea st
India. Nelumbo 58: 1–43.
Taram M and Borah D. 2020. Rhynchotechum nirijuliense (Gesneriaceae), a new species
from Northeast India. Gardens’ Bulletin Singapore 72(1): 125–129.
Taram M, Borah D, Mipun P, Taram V and Das AP. 2020c. Evaluation of ethnobotanical
knowledge in Komkar-Adi Biocultural Landscape of Eastern Himalayan Region of India.
Asian Journal of Ethnobiology 3(2): 70-87.
Taram M, Borah D, Tag H and Choudhery RK. 2020b. An inventory of th e native flowering
plants in East Siang D istrict of Arunachal Pradesh, India. Journal of Threatened
Taxa 12(17):17299 -17322. DOI:10.11609/jott.6241.12.17.17299-17322
Taram M, Hui PK and Hui T. 2021. Ethnobotanical uses of Gesneriaceae members by th e
indigenous t ribal communities in Arunachal Pradesh (India). Pleione 15(3):425-433.
Doi10.26679/Pleione.15.3.2021.425-233.
Taram M, Mipun P an d Borah D. 2020a. Rh ynchotechum parv iflorum Blume
(Gesneriaceae): a new record to mainland India. Journal of Threatened Taxa. 12(1): 15208–
15211.
Wang WT, Pan KY, Li ZY, Weitzman AL and Skog LE. 1998. Gesneriaceae. In: Wu, Z.Y. &
Raven, P.H. (Eds) Flora of China Vol. 18, pp. 244–401. Beijing: Science Press; St. Louis:
Missouri Botanical Garden Press.
Weber A, Clark JL and Moller M. 2013. A new formal classification of Gesneriaceae. Selbyana
31(2): 68-94.
Website consulted:
BSI Herbaria (https://archieve.bsi.gov.in) [Accessed on 27 March 2022]
Flora of china @ efloras.org www.efloras.org.flora_page.floraid=2 [Accessed on 13.03. 2019]
Gesneriaceae Resource Centre. h ttps://padme.rbge.org.uk/GRC. Royal Botanic Garden
Edinburgh. [Accessed on 24 May 2022]
Kew Herbarium Catalogue (http://apps.kew.org>herbcat) [Accessed on 29 March 2022]
RBGE Herbarium Catalogue (https://www.rbge.org.uk) [Accessed on 29 March 2022]
PE Herbarium (http://pe.incas.ac.cn>) [Accessed on 23 February 2022]
53
©JBR2022 Published by Centre with Potential for Excellence in Biodiversity, Rajiv Gandhi University, Rono Hills, Doimukh -791112, Itanagar, Arunachal Pradesh,
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