Bulletin of Arunachal Forest Research, Vol. 33(1), 44-51: 2018 ISSN 0970-9487 THE TAXONOMIC INVESTIGATION ON GENUS ALPINIA ROXB. (ZINGIBERACEAE) FROM THE SIANG VALLEY, ARUNACHAL PRADESH Tatum Mibang*1, Arup K. Das2 1Department of Botany, J.N. College, Pasighat- 791103, Arunachal Pradesh, India 2Department of Botany, Rajiv Gandhi University, Itanagar, Arunachal Pradesh, India E-mail: [email protected] Abstract The Genus Alpinia Roxb. distributes in the tropical and sub-tropical regions of the world. The Siang Valley of Arunachal Pradesh is favorable for the growth of the Genus Alpinia. The extensive taxonomic investigation on the Genus Alpinia in the Siang Valley resulting to 5 (five) species. For better description and understanding, a color photograph of each species are given. Keywords: Alpinia; Taxonomic investigation; Siang Valley INTRODUCTION forest crisscrossed with rivers and streams which is favorable for growth of Zingiberaceae The Genus Alpinia Roxb. consists of 241 species in the Valley. The geographical species (The Plant List, 2010) in World, parameters like altitudes ranges from 130 - mainly distributed in the tropical and sub- 900 m (Ruksin - Pekii Modi), temperature tropical region of South Asian countries. The range from 16 - 34 °C, relative humidity 54 - Genus is characterized by the tall leafy shoot, 98 % and sandy loamy soil enhance the distichous leaves, the plane of distichous is luxurious growth of various Zingiberaceae transverse to the rhizome, terminal species in the Valley. Out of 10 Genera inflorescence with large spectabilis labellum reported (Tatum, 2016) of the family and the staminode absent or rudiment tooth Zingiberaceae from the Siang Valley, Alpinia like or well elaborated horn like arching over is one of the interested genera in the family the basal part of labellum. Zingiberaceae. After extensive exploration of The genus was estimated to 230 species in the family Zingiberaceae in the Siang Valley, Indian sub-continent (Baker, 1890-1892). S. only 5 species of Alpinia has been enumerated K. Jain and Ved Prakash estimated 11 species so far. in India (1995). Of these, in North East India, Detailed taxonomic description, keys, only 5 species have been reported. Rao and habitats and ecology of each species has been Verma (1972) also reported 5 species from the provided. Photographs of the recorded species region. In south India, 8 species were reported from Siang Valley have also been provided for (Mangaly and Sabu, 1992). In Arunachal better understanding and identification. Pradesh, only 3 species has been reported so far (Chowdery, Giri and Pramanik, 2009). Taxonomic treatments After Rao and Verma (1972), the taxonomic Key to Species investigation on the Genus is considered to be 1a Inflorescence panicle; bracteoles small not progressing at the snail speed. completely enclosing floral buds………go to 2 The Siang Valley of Arunachal Pradesh 2a Leaves linear, capsule pubescence and pink falls under tropical to sub-tropical evergreen (mature)……………………Alpinia calcarata http://sfribulletin.org.in/vol-33-issue-1-2018/ Mibang and Das, 2018: TAXONOMIC INVESTIGATION ON GENUS ALPINIA 2b leaves oblong-lanceolate, capsule globose, leaves), beneath densely pubescence, oblong glabrous and black (mature)……Alpinia nigra (lower leaves) or elliptical-lanceolate (upper 1b Inflorescence raceme, bracteole large and leaves), margin pale dull with undulate, apex enclosing floral buds…………..………go to 3 acuminate, mucronate, 60-118 cm long x 15- 3a Bracteoles and calyx purplish 26 cm wide (old leaves). Inflorescence- brown………………...…Alpinia kwangsiensis raceme, terminal, emerge from upper most 3b Bracteole green, calyx pale leafy bract, erect or slightly bent up right; leafy green…...………………………………go to 4 bract- ovate, green then later on dry, minute 4a Leaves beneath glabrous, leafy stem pubescence, enclosed inflorescence part, 28-36 slender and glabrous……………………… cm long; peduncle- cylindrical, pale greenish- ……….…Alpinia blepherocalyx var. glabrior yellow pubescence, pale green, 9 cm long x 2 4b Leaves densely stiff pubescence beneath, cm wide, curved perpendicularly at 45-90 leafy stem stout and robust…………………… degree, flowers arrange in spirally on rachis, .…..Alpinia blepherocalyx var. blepherocalyx. rachis five ridges with densely pubescence. Flower- pedicel- green, tomentose, 1. Alpinia blepharocalyx K. Schumann cylindrical, slightly elongate during fruiting, var. blepharocalyx T.L. Wu 0.5 cm long x 0.3 cm wide; flower- large, Alpinia blepharocalyx K. Schumann var. white and showy; floral tube pale purple and blepharocalyx T.L. Wu Acta Phytotax. Sin., pubescence. Bracteole- tubular/navicular, pale 16(3):35, 1978. Alpinia bracteata Roxburgh green turn to dull brownish later on, dry and (1820); Alpinia malaccensis (Burm.f.) Rosc. brittle, open at one side, coarse with dull- Rao & Verma, Material toward the Fl. Assam- brownish stiff pubescence, apex 3-dentate, II, 140, 1972; Wu Delin & Larsen, Fl. China, early deciduous, 1-flowered, apical part with 24:339, 2000; Alpinia malaccensis (Burm.f.) dense stiff hairy, 3.5-4 cm long x 1.2 cm wide. Rosc., Chowdery et al., Material for Fl. Calyx- base tubular, pale greenish white, apex Arunachal Pradesh, 3:169, 2009. 2-3-lobed, apex ciliate at the margin, open at Type: Alpinia blepharocalyx K. Schumann one side, pubescence, 2.5 cm long x 2 cm var. blepharocalyx T.L. Wu (1978). board (open). Corolla- petal 3-lobes, white, pubescence, ciliate at margin; anterior lobe- Taxonomic description: Culm forming tall larger, lanceo-sub-orbicular, watery strips herb with minute stiff pubescence. Root prominent, apex cuspidate/hooded, 3-4.5 cm stock- rhizome- woody, fleshy, inner fibrous, long x 2.5-3.5 cm wide; lateral lobe –oblong- 0.5 cm wide; root- primary root prominent, lanceolate, watery strips presence, lateral lobe branched, woody. Leafy stem- culm consists adnate to labellum at basal part, 3-4.5 cm long of 8-10 plants, stout, green, tomentose, x 2-2.5 cm wide. Staminode- two, horn-like, slender, base covered with 3- bladeless subulate, deep red, adnate to labellum base, sheaths, 300-400 cm x 2-3 cm wide. Leaves- inner deep red while outer pale red, arch over distichous, 8 cm apart, pubescence beneath the filament, 0.7 cm long x 0.1 cm wide. especially along mid-vein, mid-vein striated; Labellum- ovate-sub-orbicular, lower part ligule- bi-lobed, 1.5 cm long x 1.6 cm wide; deep red with yellow band, yellow band part petiole- dirty pubescence, 6 cm long x 0.8 cm branched at apex, base and mid part thicker, wide and chaniculate; blade- base sometime margin thinner and crisp, margin of lower part oblique (lower leaves) or rounded (upper pale white to pale yellow, margin of upper part 45 BULLETIN OF ARUNACHAL FOREST RESEARCH, 33(1): 2018 pale yellow, apex acute with minute Pflanzenr., 20(46):334, 1904; Alpinia emarginate, 3.5-4.5 cm long x 4-5 cm wide; bracteata Roxb. Rao & Verma, Material claw- short, deep red, deflexed, 1cm long x 0.5 toward the Flora of Assam-II, 139, 1972; Wu cm wide. Stamen- fertile stamen I; filament- Delin & Larsen, Fl. China 24:339, 2000; short, lower deep red, upper pale red, adaxially Pantilunglu Daimeil and Yogendra Kumar, sparsely pubescence, 1 cm long x 0.3 cm wide; Pleione, 7(2):567-570, 2013. anther- 2-cell, each cell linear, pale yellow, Type: Alpinia blepharocalyx var. glabrior diverge apically, 1.5 cm long x 0.3 cm wide, (Handel-Mazzetti) T. L. Wu. theca sparsely pubescence. Pollen grain- pale Taxonomic description: Robust and culm whites, many, spherical with radiating spines. forming plant. Root stock- rhizome- Gynoecium- ovary- oval, pedicellate, pale woody/semi-woody, fibrous, 0.5 cm wide; green, densely grey pubescence, tri-locular root- primary root prominent, long, branched, with many oval ovules in axile placentation, semi-woody. Leafy-stem- culm consists of 20- 0.5 cm long x 0.4 cm wide; glands- 2, short, 40 plants, green, glabrous, slender, base board, pale yellow, clavate, 0.5 cm long x 0.3 covered with 3- bladeless sheaths, 100-400 cm cm wide; style- filiform, reddish up to mid- x 2-3 cm wide. Leaves- 12-15 per plant, 1-2 part, apical part pale yellow, 4 cm long x 0.1 smaller leaves at base, 8-45 cm leaves cm wide; stigma- funnel shape, exerted above apart/distance, usually concentrate at apical anther, pubescence and margin ciliate. part; ligule- unequal bi-lobed, inner surface Capsule/fruits- globose-oval, densely with deep green blotch, 0.8-1 cm long x 15-1.7 pubescence, green-pale yellow, red on cm wide, sparsely minute pubescence; petiole- ripening, 3-valves, 2-3 cm long x 1.8-2 cm chaniculate, sparsely minute pubescence, wide; seeds- ovoid, many, grey yellow-dull lower leaves with shorter and bigger petiole, brown, aromatic. 0.4-4 cm long x 0.4-0.7 cm wide; leaf blade- Phenology: Flowering March-June, fruiting lower leaves ovate, upper leaves oblong- April-December. lanceolate, base rounded/attuneate, margin Ecology: The plant naturally occurs in primary entire and undulate, upper surface glabrous forest in wet-shady area along the slope of with conspicuous strips especially near the stream side. It prefers to grow in mountainous margin, beneath pale green and glabrous, apex loamy soil at altitude 400-500 m. acuminate, 24-76 cm long x 15-20 cm wide. Distribution: North East (India), China, Inflorescence- raceme, terminal; peduncle- Thailand, Vietnam. green, tomentose, base dilated, stout; rachis- pale green, pubescence,4-5 ridges, 20-30 cm Note: The species is almost similar to A. long x 0.8-1 cm wide; Bracteole- navicular blepharocalyx var. glabrior except leaf blade with 2-3 prominent ridges, obovate, tubular, is densely pubescence abaxially, especially open at side opposite to labellum, inner surface along the mid-rib. with prominent strips, minute ciliate at apical 2. Alpinia blepharocalyx var. glabrior margin, 4 cm long x 1 cm wide (closed), green (Handel-Mazzetti) T.L.