Osbeckia nutans Wall. ex C.B.Clarke

P., Prashob & Thomas, Sibichen M., 2019, The genus Osbeckia (Melastomataceae) in India, Rheedea 29 (4), pp. 236-305 : 264-266

Osbeckia nutans Wall. ex C.B.Clarke in Hook.f., Fl. Brit. India 2: 521. 1879; C.Hansen, Ginkgoana 4: 75. 1977; N.P.Balakr., Fl. Jowai 206. 141. 1983; Hajra & Verma, Fl. Sikkim 296, 1996; Noltie, Fl. Bhutan 1994. O. nepalensis Hook. var. nutans (Wall. ex C.B.Clarke) D. Maity, Econ. Taxon. Bot. (27) 1235. 2003. syn. nov. Lectotype (designated by Hansen, 1977): INDIA, s.loc., s.d., Wallich 4068 (K000867997 digital image!).

O. nutans Wall., Numer. List 144, no. 4068. 1831, nom. nud. Fig. 12

Perennial, erect, branched shrubs, c. 1.5 m tall. Stems covered with appressed hairs. Petioles 1–3 mm long; lamina narrowly lanceolate, 3–6.5 × 0.5– 1 cm, 3-nerved, apex acute, base obtuse, glabrous throughout except on nerves below. Panicles terminal, 4–6-flowered, subtended by a pair of reduced leaves. Flowers pentamerous; pedicels 3–5 mm long; bracts green, ovate to cordate 4–7 mm long, both sides spatially clothed with short hairs. Hypanthium campanulate, 4–4.5 × 4–4.5 mm, glabrous or with appressed scale like emergences having hairs at apex; intersepalar emergences exactly resembles normal emergences, both are caducous. Sepals 5, triangular, 6.5–7.5 mm long, with a few indistinct nerves, minutely ciliate, otherwise glabrous, caducous. Petals 5, obovate, 13–16 mm long, pink or purple, apex ciliate. Stamens 10; filaments 4–6 mm long; anthers narrowly ovate to oblong, 3–6 mm long, not twisted, pore oblique on ventral side of the tip; connective slightly prolonged into an undulating lobed collar. Ovary united with hypanthium; anther pockets extending to base of ovary, free part densely covered with appressed hairs; crown small, distinct, with short hairs; style 13–14 mm long. Capsules campanulate, 6.5–8.5 × 5–6.5 mm; seeds minute, curved, 0.1– 0.2 mm long, numerous.

Flowering & fruiting: August–March.

Chromosome number: Not reported

Habitat: Occurs in swampy areas and river margins.

Distribution: Bhutan, India Myanmar and Nepal.

Specimen examined: INDIA, Arunachal Pradesh, Changlang district, Namdapha National Park, 10.06.1982, J. Joseph 81114 (ASSAM); Vijaynagar, 26.12.1996, Das Chauhan 99555 (ASSAM); Lohit district, Chamba village, 17.12.1969, A.S. Rao 48687 (CAL, ASSAM); Deopani river, north of Roing, 03.10.1969, A.S. Rao 48210 (CAL, ASSAM); Zunglua-Rusa, 05.09.1958, G. Panigrahi 16775 (CAL); Papum Pare district, Kimin to Zero, 23.11.1957, G. Panigrahi 11465 (ASSAM); Subansiri district, Subansiri Reserve forest Kimin-Kumin, 24.09.1959, G. Panigrahi 19302 (CAL, ASSAM); West Kameng district, Chaku, 21.04.1957, G. Panigrahi 6307 (CAL, ASSAM); Champari, 03.12.1916 H. Haines s.n. (CAL); Kameng, s.d., A.S. Rao 50761 (ASSAM); Kameng, Chopai forest camp, 18.02.1974, A.S. Rao 56443 (ASSAM); Orchid Research centre, Tippi, 30.06.2015, Prashob & Sibichen 6117 (DEV); Shukhanala, s.d., P.K. Hajra 54483 (ASSAM); Sissini to foot hill camp, 18.04.1957, G. Panigrahi 7042 (ASSAM); Tippi to Balupara 16.09.2016, Prashob & Arun 6117 (DEV); Tirap district, Zunghua-Rusa, 05.09.1958, G. Panigrahi 16775 (ASSAM). Assam, Goalpara district, s.loc., 03.12.1918, Upendranath Kanjilal 7450 (ASSAM); Kokrajhar district, Chakoarila W.L.S, 03.07.2003, Ranjit Daimary 118075 (ASSAM); Lakhimpur district, Kimin river, 23.11.1957, G. Panigrahi 11465 (CAL, ASSAM); North Lakhimpur, Naharani Reserve, 17.05.1966, D.M. Verma 46390 (ASSAM); Subansiri Reserve forest Lakhimpur, 24.09.1959, G. Panigrahi 16775 (CAL); Upper Assam, Dikhow river forest, 30.03.1895, s.coll. 11093 (CAL). Manipur, Chamoo, 14.01.1882, George Watt 172153 (CAL); Naga hills, 12.1907, A. Meebold 7339 (CAL). Meghalaya, East khasi hills district, Shillong, s.d. Griffith s.n. (CAL); Garo hills district, Napak lake, 19.07.1976, M.K.V. Rao 64614 (ASSAM); Jaintia hills district, 17.12.1911, I.H. Burkill s.n. (CAL); West Jaintia Hills, Nartiang, 28.08.1968, N.P. Balakrishnan 47194 (ASSAM). Sikkim, East Sikkim district, Bumbing on the way to Rangto, 19.12.1981, P. Chakrabarty 2001 (BSHC); s.loc. 18.12.1903, Prain 25 (CAL); East Sikkim, 25.07.1985, D.C.S. Raju 3921 (BSHC); 20 th Mile side, Bordang, 17.11.2001, S.S. Dash & S.K. Rai 23920 (BSHC); East Sikkim, 24.11.1980, S.B. Ram 00870 (CAL); Rangpo, Namthang, 19.12.1981, P. Chakrabarty 867 (CAL); Rhenock, 24.11.1980, S.B. Ram 00841 (BSHC); Rongly, 07.12.1980, P. Chakrabarty 1030 (CAL); Reshi, 02.01.1996, S.K. Jana 18013 (BSHC); way to Rongli, 07.12.1980, P. Chakrabarty 1030 (BSHC); South Sikkim district, Teesta valley, 15.11.1901, Prain s.n. (CAL); West Sikkim district, Labdang, 11.1990, Dr. Prain 60 (CAL); Sikkim, 10.1874, C.B. Clarke 28650 (CAL).

Notes: Osbeckia nutans can be recognized by its lanceolate leaves and large sepals exceeding the hypanthium. It is interesting to note that both glabrous or hypanthium with scaly emergences are found on the same plant.

Maity (2003) treated O. nutans as a variety of O. nepalensis . But critical examination of the type, protologue and live specimens led us to reinstate its original species status. Leaves are small (3–6.5 × 0.5–1cm), narrow, petiolate and glabrous in O. nutans whereas it is large (5–16 × 2–5.5 cm), sessile, with shaggy hairs in O. nepalensis .

Figures

Fig. 12. OSbeCkia NUtaNS Wall.eX C.B.ClaRke: aa.. Habit; b. HypaNthiUM; C.CalyX lObe; d. INteRSepalaR eMeRgeNCe;ee.. StaMeNS; F. SeedS.