Three new Angiospermic (Orchidaceae) records from Bangladesh

Coelogyne schwadtkii Danell., Cleisostoma williamsonii (Rchb.) Garay. and Phalaenopsis difformis (Wall. ex Lindl.) Kocyan & Schuit. of the family Orchidaceae collected from southeast part of the country have been reported here as new angiospermic records for Bangladesh flora. Detailed critical examination of the specimens of these species has been made to confirm their taxonomic identification. Detailed taxonomic description with flowering time, ecology, geographical distribution, illustration and photographs of each species has been provided. 
Jahangirnagar University J. Biol. Sci. 9(1 & 2): 123-132, 2020 (June & December)


INTRODUCTION
The family Orchidaceae belongs to the Lilliopsida of flowering plants. It is one of the most fascinating groups of ornamental plants of the world occurring mostly in the tropical and subtropical parts of the world with 880 genera and about 26567 species (Cai et al., 2015), a few of them are also found in arctic regions. This family represents 579 species in Bhutan (Pearce & Cribb, 2002), 1388 species (including 491 endemic) in China (Lang et al., 1999), 1350 species under 185 genera in India (Hegde, 1997), and 450 species in Nepal (Pant et al., 2016). In Bangladesh, the family is represented by 72 genera and 188 species (Rahman et al., 2017). William Roxburgh (1814) for the first time recorded 12 species of orchids in his Hortus Bengalensis (nom. nud.) from Bangladesh and later he described 28 species in his Flora indica (Roxburgh, 1832). Subsequent by Wallich (1786Wallich ( -1854 recorded 27 species, Hooker (1885Hooker ( -18901890-1894 79 species, Prain (1903) 74 species, Heinig (1925) 49 species, Datta & Mitra (1953) 13 species and Sinclair (1956) 19 species around the world. Since the independence of Bangladesh in 1971, a number of workers have made remarkable contributions to the account of the Orchidaceae from its flora, such as, Seidenfaden (1978Seidenfaden ( , 1978aSeidenfaden ( , 1985Seidenfaden ( , 1988, Moyeen (1982), Biswajit (1987), Khan & Halim (1987, , Ahmed & Pasha (1993, 1994, 1998a, Rahman & Huda (1998, , Huda et al., ( , 2001, Khamum et al., (2001), Huda (2007) and Rahman et al., (2017). According to upto date literature, three species of the genus Cleisostoma, five species of Coelogyne and three species of Phalaenopsis have been reported so far from Bangladesh (Huda, 2008). Therefore, three more species under above mentioned three genera have been reported here for the first time from Bangladesh. Orchid flora of Bangladesh is not yet prepared completely and it is still being explored. The present work is aimed at discovering unexplored orchids from different remote areas of Bangladesh based on extensive field works towards completion of the orchid flora of Bangladesh.

MATERIALS AND METHODS
The specimens were collected from the remote areas of Boga Lake Para, Ruma, Bandarban and Shadi beat, Jaflong, Jaintiapor, Jaintia hill, Sylhet district of Bangladesh. The collected plants were grown at the orchidarium. After bloom the flowers of each of the species were dissected and critically examined under microscope and then identified with the consultation of the relevant literature (Prain, 1903;Heinig, 1925;Datta & Mitra, 1953;Sinclair, 1955;Pearce & Cribb, 2002;Rahman et al., 2017). The voucher specimens of each species have been deposited at the Herbarium of Chittagong University (HCU), Bangladesh.
Flowering and fruiting time: Early February -mid March.

Ecology:
The orchid was collected in vegetative stage from Litsea polyantha Juss. plant at the height of approximately 10 m. It was also found to associate with Ferns. Only one or two vegetative parts of the species were found in the area.

Uses: Unknown
Uses: Headache, numbness and pain (Williamsoni, 1972). Differs from the other species column with apical stelidia, glabrous; stipe broadly ovate-triangular or miter-shaped; viscidium crescent-shaped.  Description: Epiphytic, stem very short bearing few leaves, 7-16 x 3-4 cm, sessile, spreading, coriaceous, elliptic oblong, acute, flat, narrowed at the base. Inflorescence pendulous, many-flowered, much longer than the leaves, 20-30 cm long. Flowers 1.2 cm across, greenish-yellow with brown bands. Bracts much shorter than ovary, lanceolate 3 mm long. Sepals spreading or reflexed, unequal, oblong-ovate, obtuse, yellow, streaked with red. Petals similar to sepals but smaller. Lip much longer than the sepals; apical lobe divided into 3 lobules; side lobes subquadrate, recurved with pectinate margin; central lobule triangular, in fold and with entire margin, abroad long claw and an incurved sub cylindric spur joint to the apical lobe, two calli at the mouth of the spur; column short, cylindric, stout with a short foot; rostellum forked; stigma circular, surrounded by hairy rim attached to the short foot of the column by claw and epichile with 2-lateral recurved pectinate lobules.

Flowering and fruiting time:
Late June-early July.
Ecology: Epiphytic and grows on trees especially on Glochidion velutinum Wight. Trees at 20m high altitude, evergreen forest, and large clumps occur on trunk of the trees.