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Vol. 13(7), pp. 2-18The McAllen International Orchid Society JournalJuly 2012

Peer-Reviewed Article
Effective Publication Date : 1-Jul-2012

The Current Ecological Status, Diversity Resources, and Distribution of Cymbidium Orchid Species in Darjeeling Himalaya of India

Rajendra Yonzone,1* D. Lama,1 R. B. Bhujel,2 Khyanjeet Gogoi,3 and Samuel Rai4

1 Department of Botany, St. Joseph's College, P.O. North Point, District Darjeeling, W. B., India 734104
2 Taxonomy & Ethnobiology Research Laboratory, Cluny Women's College, P.O. Kalimpong, District Darjeeling, W. B., India 734301
3 Disa Bordoloi Nagar, Talap, Tinsukia, Assam, India 786156
4 Darjeeling Krishi Vigyan Kendra, Uttar Banga Krishi Viswavidyalaya, P.O. Kalimpong, District Darjeeling, W. B., India 734301
* Corresponding author E-mail: ryonzone99@gmail.com
(Note: Figures not otherwise noted are attributed to first author.)

Abstract

Darjeeling Himalaya is the Northern most district of West Bengal, India that covers the hill and mountains that includes the alpine zone in Sandakphu and Phalut to foot hill in Terai at Siliguri with a vast stretches of the plains. This region is home for a number of orchid species including several Cymbidium species. In the present investigation, 12 species of Cymbidium were found to occur in Darjeeling Himalaya. Of these all were epiphytic except C. devonianum frequently found in lithophytic habitat. These species flower from March-May to October-December. They were found at 150m at Sevoke - Siliguri, Sukuna forest (Cymbidium aloifolium) to as high as 2800m at Neora Valley Cymbidium erythraeum C. lowianum, C. mastersii etc. There is no report by earlier workers on ecological status of Cymbidium from Darjeeling Himalaya. In the present investigation Raunkiaer's Ecological Statistics, given by Raunkiaer, (1934) were carried out to find out the current status of these species from Darjeeling Himalaya. Then, a painful investigation to find out current status of the genus was undertaken and the following conclusions were drawn. Out of 12 species found in Darjeeling Himalaya, 3 species were frequent, 2 were sparse, 5 were rare and 2 threatened.

Key Words

Cymbidium orchid species, Diversity resources, Distribution, Current status, Darjeeling Himalaya, India.

Introduction

Orchids are considered to be the most highly evolved in the floral specialization and diversified form among the monocotyledons. In India, orchids form 9% of our flora and are the largest and highest advanced botanical family of higher plants. It is estimated that at about 25,000-35,000 species with 800-1,000 genera are distributed throughout the world. About 1300 species with 140 genera of orchid species are found in India with the temperate Himalayas as their natural home (Yonzone and Kamran, 2008).

Fig. 1. Location of Darjeeling district (study area) of West Bengal, India.

Darjeeling Himalaya is the northernmost part of West Bengal, India. It is comprised of four subdivisions viz., Darjeeling sadar; Kalimpong, Kurseong and Siliguri (Fig. 1). The region lies between 26°31' and 27°31' north latitude and between 87°59' and 88°53' east longitude in the eastern Himalayan region of India. It is bordered by Sikkim in the north, Terai and Dooars in the south, Bhutan in the east and Nepal in the west. Broadly speaking, it has two topographical features. Darjeeling, Kurseong and Kalimpong form the hill areas whereas Siliguri is stationed at the foothill in a vast stretch of the plains. It falls in Darjeeling district having triangular shape. The total area of the triangular shaped district is 3,254.7 sq. km. which is 3.68 percent of the total area of West Bengal state. The hilly region covers 2,320 sq. km. and the remaining 934.7 sq.km of the area falls in the Terai and plains. The altitudinal variations of the district range from 130m at Siliguri to 3,636m at Sandakphu-Phalut with a sharp physiographic contrast between the plain and the mountainous regions. It is home to number of orchid species including Cymbidium species.

The genus Cymbidium was described in 1799 by Olof Swartz (1760-1818) in Nova Acta Regiae Societatis Scientiarum Upasaliensis. The genus comprises about 50 species distributed in India, East through S.E. Asia, China, Japan, Indonesia to Australia.

Plants are epiphytic, lithophytic, terrestrial, or saprophytic; pseudobulbs short to elongate, covered by sheaths; leaves long, oblong or rarely lanceolate, coriaceous. Inflorescence is erect or curved, suberect or pendent, racemose; 1 to many-flowered; peduncle loosely sheathed. Flowers are large and showy. Sepals and petals free, spreading. Lip 3-lobed, borne on a short column foot; lateral lobes erect around the column; mid lobe recurved; disc with 1-3, glabrous or pubescent, ridges. Column long; pollinia 2. In the present investigation, the available Cymbidium Orchid species of Darjeeling Himalaya along with their current status in the region is studied.

Materials and Methods

The intensive field survey was conducted during the year 2007-2011 covering all the seasons of the year in the entire Darjeeling Himalaya including the forest areas, floral nurseries and farms. The authors also visited Singhalila National Park in Darjeeling and Neora Valley National Park in Kalimpong and remote far flung villages covering all the altitudinal ranges as low as Siliguri 150m to as high as Sandakphu-Phalut 3,636m of entire Darjeeling district of West Bengal. All the species of Cymbidium found were recorded in the field note book with their necessary information. The relevant data from the field note books were then transferred to the labels of the herbarium sheets and computer.

The plant specimens were also collected without uprooting and disturbing the plants in the nature. Normally, only 2-3 specimens of each species in flowering and fruiting stage were collected and life form photographs were prepared. The specimens so collected were processed, preserved and mounted on herbarium sheets following the standard herbarium techniques given by (Jain and Rao, 1977); and described, properly identified and authenticated with the help of Flora of British India (Hooker, 1872-1897); Flora of Bhutan (Pearce and Cribb, 2002) and from the herbarium of Department of Botany, North Bengal University, Siliguri; Central National Herbarium, Indian Botanical Garden, Sibpur, Howrah.

Drawing, dissection and data compilation work was done in the laboratory. Correct nomenclature has been checked with recent available literatures. The classification was given by King and Pantling (1898); Hedge (1984); Kataki (1986); Pradhan (1979); Chowdhery (1998); Bose and Bhattacharjee (1999); Pearce and Cribb (2002) and Lucksom (2007). There is no earlier report on the ecological status of these studied species. The ecological status by Raunkiaer's Ecological Statitistics, given by Raunkiaer, (1934) were carried out in the field. Quadrate plots of 10m x 10m for epiphytic and 5m x 5m for terrestrial species were laid down diagonally in habitat rich field to find out the current status of Cymbidium species from study areas.

Enumeration

Fig. 2. Cymbidium aloifolium. [Photo as corrected in August 2012 MIOS Journal, p. 2; Digital photo DSC_3597; Photo: R. J. Ferry].

1. Cymbidium aloifolium (L.) Sw. in Nova Acta Regiae Soc. Sci. Upsal. 6: 73. 1799. (Fig. 2)

Plant 40-64cm tall. Pseudobulbs 6-8 x 3-4cm, ovoid, bilaterally flattened, enclosed in persistent leaf bases and bladeless sheaths. Leaves 4-5, 33-59 x 2.6-3.5cm, oblong, obtuse to emarginated, unequally 2-lobed at apex, coriaceous; leaf base 4-18cm long; sheaths 6 or 7, 5-14cm long. Inflorescence 10 to 20-flowered; peduncle 4-11 cm long; sheaths 5-7, basal, overlapping, boat-shaped, acute, 3.5-7cm long; rachis 24-67cm long; floral bracts 2-5mm long. Flowers 3.5-4.2cm across, scented; sepals and petals pale yellow-cream, maroon-striped, lip white-cream, base yellow, maroon-veined, callus yellow; pedicellate-ovary 1.8-2.4cm long. Sepals similar, 2-2.4 x 0.6-0.7cm, narrowly oblong to narrowly elliptic, obtuse. Petals 1.8-2.3 x 0.5-0.8cm, narrowly elliptic, obtuse to acute, sometimes porrect. Lip 3-lobed, 1.7-2.2 x 1.1-1.4cm, saccate at base, minutely papillose-pubescent; lateral lobes erect, acute to acuminate, clasping the column; mid-lobe ovate, acute to obtuse, mucronate, recurved, entire, 0.9-1.3 x 0.65-0.9cm. Column 1.1-1.3cm long, curved, winged at apex; foot short; Anther 0.2 x 0.1mm. Pollinia 2, cleft.

Voucher specimen: [Rajendra et al 0362]; Habitat: Epiphytic; Altitudinal ranges: 150-1600m; Date of collection: 11 May 2008; Flowering: April-July; Status: Sparse; Local distribution within Darjeeling: Forest areas in Relli, Sevoke - Siliguri sub-division; Suruk-Kalimpong 7th mile, Chitrey - Kalimpong sub-division; Sukuna, Tindharey - Kurseong sub-division; General distribution: India, Nepal, S. China, Myanmar, Thailand, S.E. Asia, Malaysia and Java.

Fig. 3. Cymbidium cochleare.

2. Cymbidium cochleare Lindl. in J. Proc. Linn. Soc., Bot. 3: 28. 1858. (Fig. 3)

Plant 32-58cm tall. Pseudobulbs 6-7 x 2.5cm, narrowly ovoid. Leaves 9-13, 57-92 x 1.1-1.3cm, distichous, tapering to an acute apex, jointed; leaf base broad, 2.7-6 cm long, sheathing; bladeless sheaths 5, scarious, sheathing. Inflorescence 8 to 16-flowered; peduncle suberect to horizontal; sheaths boat-shaped; rachis slender, pendent; floral bracts ca. 5 mm long, scarious. Flowers ca. 2.5cm, campanulate, waxy, pendent; sepals and petals greenish-brown, margins pale, lip yellow or orange-yellow, red-brown spotted, column white-green; pedicellate-ovary 1.6-2.2cm long. Sepals similar, 4.5-4.9 x 0.9-1.1cm, narrowly obovate, acute; dorsal sepal porrect; lateral sepals mucronate, not spreading. Petals 4.4-4.8 x 0.6-0.8cm, narrowly oblong-obovate, subacute, weakly falcate, porrect. Lip 4.2-4.6 x1.1-1.3cm, slender, deltoid, 3-lobed, adnate to column base for 2mm; lateral lobes 0.9-1.1cm broad, triangular, subacute, erect, glabrous; mid-lobe 0.8-1 x 0.8-1cm, cordate-elliptic, mucronate, porrect, margin minutely undulate,; callus 2-ridged, puberulent, the sides united, shell-shaped towards apex. Column 3.4-3.8cm long, slender, deflexed at apex, puberulent. Anther 0.4 x 0.3cm. Pollinia 0.2 x 0.1cm.

Voucher specimen: [Rajendra et al 1011]; Habitat: Epiphytic; Altitudinal ranges: 1500-2200m; Date of collection: 4 November 2009; Flowering: October-December; Status: Sparse; Local distribution within Darjeeling: Forest areas in Charkhol, Lava - Kalimpong sub-division; Takdah - Darjeeling sub-division; General distribution: N. India, China and Taiwan.

Fig. 4. Cymbidium dayanum; Photo Credit: OrchidWiz, USA, Image 1240; http://www.orchidwiz.com.

3. Cymbidium dayanum Reichb. f. in Gard. Chron. 1869: 710. 1869. (Fig. 4)

Plant 27-83cm tall. Pseudobulbs 3.8-4.2cm long, fusiform, covered by sheaths. Leaves 5-7, 31-83 x 0.9-1.5cm, distichous, linear-elliptic, acute to acuminate, dark green, coriaceous; leaf base 3-7 cm long. Inflorescence 8 to 13-flowered; peduncle 6-8cm long, suberect to horizontal, covered with sheaths; sheaths pink veined; rachis 7-13cm long; floral bracts 0.5-0.9cm long, acute. Flowers 4-4.8cm across, unscented; sepals and petals white to cream, central stripe maroon, lip white, strongly marked with maroon and yellow, callus white to cream, column maroon; pedicellate-ovary 2-2.8cm long. Sepals subsimilar, 2.6-3 x 0.7-0.8cm narrowly elliptic to oblong-lanceolate, acute to shortly acuminate, erect; lateral sepals 2.6-3.1 x 0.8-0.9cm. Petals narrowly oblong to elliptic, obtuse to acute, porrect, covering thecolumn, 2-2.6 x 0.6-0.7cm. Lip 3-lobed, 1.8-2.1 x 1.2-1.4cm; lateral lobes erect, clasping the column, tips triangular, porrect; mid-lobe ovate, entire, recurved, mucronate, minutely papillose; callus 2-ridged, glandular pubescent, Column 1.1-1.3cm long, curved. Anther 0.2 x 0.2cm, yellow; Pollinia 1.1 x 1mm, yellow.

Voucher specimen: [Rajendra et al 1471]; Habitat: Epiphytic; Altitudinal ranges: 500-2200m; Date of collection: 22 September 2010; Flowering: August-November; Status: Rare; Local distribution within Darjeeling: Forest areas in Jaldhaka - Kalimpong sub-division; Lathpanjar, Mungpoo - Kurseong sub-division; General distribution: N India, Thailand, China, Cambodia, Taiwan, the Ryukyu Islands, Japan, the Philippines, W. Malaysia, Sumatra and Sabah.

Fig. 5. Cymbidium devonianum.

4. Cymbidium devonianum Lindl. ex Paxton in Paxton's Mag. Bot. 10: 97. 1843. (Fig. 5)

Plant 26-38cm tall. Pseudobulbs 2-3 x 1.4-1.9cm, ovoid, covered by leaf bases and bladeless sheaths; sheaths 5 or 6, 9-10cm long. Leaves 2-4, 12-26 x 3.2-5cm, elliptic, obtuse to subacute, oblique, mucronate, midrib prominent; leaf base petiolate, 10-12cm long. Inflorescence pendent, subsecund, densely 10 to 25-flowered; peduncle 6-9cm long, sheathed; sheaths 6 or 7, ca. 6cm long, boat-shaped; rachis 10-23cm long; floral bracts triangular, acute, 2-4mm long. Flowers 2.6-3.3cm across, scented; sepals and petals pale yellow to dull olive-green, mottled with purple-brown, lip purple with dark maroon blotch on lateral lobes, disc cream, column greenish; pedicellate-ovary 1.3-1.7cm long. Sepals subsimilar, 2-2.7 x 0.8-1cm, elliptic, obtuse. Petals 1.8-2.2 x 0.7-0.9cm, subquadrate, subacute to acute. Lip broad, 1.5-1.6 x 1.1-1.4cm, rhombic, minutely papillose, weakly 3-lobed, attached to short column foot; lateral lobes obscure; mid-lobe 8 x 8mm, triangular-ovate; callus reduced to 2 small swellings at base. Column 1.1-1.3cm, clavate, winged at apex; foot short. Anther 4 x 3mm. Pollinia 2, 1.2 x 0.8mm, light yellow.

Voucher specimen: [Rajendra et al 0349]; Habitat: Epiphytic and frequently Lithophytic; Altitudinal ranges: 1300-2300m; Date of collection: 28 April 2008; Flowering: April-July; Status: Frequent; Local distribution within Darjeeling: Forest areas in Lungshel, Lava - Kalimpong sub-division; Toroyok Busty - Kurseong sub-division; Jorebangalow - Darjeeling sub-division; General distribution: Nepal, N.E. India, Myanmar, S. China and N. Thailand.

Fig. 6. Cymbidium elegans var. elegans.

5. Cymbidium elegans var. elegans Lindl. Gen Sp. Orchid. Pl.: 1833. Synonym: Cymbidium longifolium D. Don, Prodr. Fl. Nepal.: 36 1825. (Fig. 6)

Plant 32-57cm tall. Pseudobulbs 5.6-7.5 x 3-3.8cm, ovoid. Leaves 7-11, 33-61 x 1.6-2cm, distichous, elliptic, acute, minutely 2-lobed at apex; leaf base sheathing, 5-10 cm long. Inflorescence densely 17 to 29-flowered; peduncle 13-19cm long, suberect to horizontal, sheathed; rachis 11-23cm long; floral bracts 1-6mm long. Flowers 3.7-4cm across, pendent, campanulate, cream to straw-yellow, tinged pink, lip cream to pale green, sparsely red-spotted, callus orange-yellow; pedicellate-ovary 1.7-2.1cm long. Sepals similar, 3.5-4.4 x 0.8-1cm, narrowly obovate, acute, concave; dorsal sepal porrect, covering column; lateral sepals not spreading, mucronate. Petals 3.3-4.1 x 0.6-0.7cm, narrowly oblong-obovate, obtuse, weakly falcate, porrect. Lip 3-lobed, deltoid, elongate, adnate to base of column for 2-3mm; lateral lobes 0.6-0.8cm broad, triangular, erect or clasping the column, apex acute to subacute, entire; mid-lobe 0.6-1 x 0.4-0.8cm, small, base oblong, apex 2-lobed, emarginated, centrally pubescent, margins undulate; callus 2-ridged. Column slender, 3-3.7cm long, puberulent, narrowly winged. Anther 3 x 2mm; Pollinia 4, 1.4 x 1.1mm, orange yellow.

Voucher specimen: [Rajendra et al 0724]; Habitat: Epiphytic; Altitudinal ranges: 1000-2300m; Date of collection: 23 October 2008; Flowering: October-December; Status: Rare; Local distribution within Darjeeling: Forest areas in Lava, Gumbadara, Algarah - Kalimpong sub-division; Lopchu - Darjeeling sub-division; General distribution: Nepal, N.E. India, Myanmar and S.W. China.

Fig. 7. Cymbidium erythraeum. Photo Credit: OrchidWiz, USA.

6. Cymbidium erythraeum Lindl. In J. Proc. Linn. Soc., Bot. 3: 30. 1859. (Fig. 7)

Plant 36-74cm tall. Pseudobulbs 4-8 x 3-5cm, ovoid. Leaves 8-13, 31-70 x 1-1.8cm, distichous, linear-oblong, tapering to fine point; leaf base 3.7-5.4cm long, sheathing. Inflorescence erect to horizontal, arching, 5 to 14-flowered; peduncle 9.5-20cm long, sheathed; sheaths 4-6cm long, scarious, lanceolate, acute; rachis 13-25cm long; floral bracts c. 4 x 1.5mm, triangular. Flowers ca. 4 x 5cm, fragrant; sepals and petals greenish, spotted and striped red-brown, lip yellowish to white, spotted red-brown, callus cream-white, column yellow, lateral lobes red-veined; pedicellate-ovary 1.2-1.8cm long. Sepals similar, narrowly obovate, acute, dorsal sepal 4-4.5 x 1.2-1.4cm. lateral sepal 4.5-4.7 x 1.1-1.4cm. Petals 4.6-4.9 x 0.6-0.8cm, oblong, acute, falcate, spreading. Lip 3-lobed, 3.1-3.5 x 1.8-2 cm, adnate to base of the column for 2-4 mm; lateral lobes 0.7-1.2 cm broad, erect, acute, pubescent-papillose; mid-lobe 0.9-1.1 x 1-1.4 cm, cordate-reniform, acute, papillose; callus 2-ridged, tapering to lip base, densely pubescent, indumendum not extending into mid-lobe. Column 2.3-2.9cm long, winged, sparsely pubescent. Anther 3-3.2 x 2mm, ovoid; Pollinia 4, obovoid, orange yellow.

Voucher specimen: [Rajendra et al 1432]; Habitat: Epiphytic or lithophytic; Altitudinal ranges: 1800-2700m; Date of collection: 17 August 2010; Flowering: August-November; Status: Rare; Local distribution within Darjeeling: Forest areas in Lava, Neora Valley, Algarah - Kalimpong sub-division; Takdah - Darjeeling sub-division; General distribution: Nepal, N. India, Myanmar and S. China.

Fig. 8. Cymbidium hookerianum.

7. Cymbidium hookerianum Rchb. f. in Gard. Chron. 1866: 7. (1866). (Fig. 8)

Plant 45-70cm tall. Pseudobulbs 4-5.5x2-3.5cm, ovoid. Leaves 6-10, 36-48 x 1.9-2.8cm, linear-elliptic, acute; leaf base 5-9cm long, sheathing. Inflorescence pendent, 9 to 16-flowered; peduncle 8-12cm long, suberect, loosely sheathed; sheaths 6-9cm long, scarious, lanceolate-ovate, acute; rachis 18-28cm long, zigzag, slender; floral bracts 4-6 x 2-3mm, triangular. Flowers 5-7cm across, strongly scented; sepals and petals apple-green, red-spotted at base, lip cream to yellow with green margins, maroon-spotted or blotched, callus cream with red spots; pedicellate-ovary 3.8-5.7cm long. Sepals subsimilar, 5.7-6 x 1.8-2cm, narrowly obovate, acute; dorsal sepal porrect; lateral sepals spreading. Petals 5.3-5.5 x 1.2-1.4cm, oblong to narrowly obovate, curved, spreading. Lip 3-lobed, 4.5-4.9cm, adnate to the column base; lateral lobes 1.2-1.5cm broad, triangular, acute to porrect, margins ciliate, papillose; mid-lobe 1.7-2 x 2.7-2.9cm, broadly ovate-cordate, mucronate, recurved, margin erose-undulate; callus 2-ridged, pubescent. Column 3.3-4cm long, winged, pubescent-papillose ventrally. Anther 4-5 x 5.5-6mm; Pollinia 2, orange-yellow.

Voucher specimen: [Rajendra et al 0921]; Habitat: Epiphytic; Altitudinal ranges: 2200-2800m; Date of collection: 10 April 2008; Flowering: March-May; Status: Threatened; Local distribution within Darjeeling: Forest areas in Jarebuttee (Neora Valley), Todey - Kalimpong sub-division; General distribution: E. Nepal, N.E. India and S.W. China.

Fig. 9. Cymbidium iridioides.

8. Cymbidium iridioides D. Don, Prodr. Fl. Nepal.: 36. 1825. (Fig. 9)

Plant 43-76cm tall. Pseudobulbs 6-13 x 2.3-5cm, narrowly ovoid. Leaves 30-46 x 1.7-3.8cm, linear-elliptic, acute; leaf base 7-13cm long, sheathing, yellow-green. Inflorescence 8 to 13-flowered; peduncle sheathed, c. 12-17cm long; rachis 23-41cm long; floral bracts 5-7 x 2-3mm, triangular. Flowers 3.6-7cm across, scented; sepals and petals yellowish-green, veined red to ginger-brown, lip yellowish, red-spotted, lateral lobes red-veined, callus yellowish spotted with maroon; pedicel and ovary 3-4.4cm long. Sepals subsimilar, narrowly obovate, acute, concave, porrect; dorsal sepal 4.5-4.8 x 1.5-1.8cm, elliptic-oblong, acute, 11-nerved; lateral sepals 4.3-4.7 x 1.2-1.7cm, elliptic-oblong, slightly falcate. Petals 4.4-4.7 x 0.8-1cm, oblong, curved, spreading. Lip 2-3 x 1.5-2.3cm, 3-lobed, adnate to the column base; lateral lobes triangular, porrect, margins fringed with short hairs, 1-1.2cm broad; mid-lobe ovate, mucronate, recurved, sparsely hairy, margins erose, pubescent; callus 2-ridged, pubescent ciliate. Column clavate, winged, 2.7-3cm long. Anther 3.5-3.8 mm long, slightly scabrid; Pollinia 4, ca. 1.3mm long, ovoid, orange-yellow.

Voucher specimen: [Rajendra et al 1745]; Habitat: Epiphytic or lithophytic; Altitudinal ranges: 1100-2400m; Date of collection: 24 November 2011; Flowering: October-November; Status: Frequent; Local distribution within Darjeeling: Forest areas in Algarah, Lava, Neora Valley - Kalimpong sub-division; Baggonra - Kurseong sub-division; General distribution: Nepal, NE India, Myanmar and SW China.

Fig. 10. Cymbidium lancifolium.

9. Cymbidium lancifolium Hook., Exot. Fl. 1: t. 51. 1823. (Fig. 10)

Homotypic Synonyms:
- Cymbidium apidistrifolium Fukuy., Bot. Mag. (Tokyo) 48: 438. 1934. [Basionym/Replaced Synonym]
- Cymbidium javanicum var. apidistrifolium (Fukuy.) F. Maek., J. Jap. Bot. 33: 320. 1958.
- Cymbidium lancifolium var. apidistrifolium (Fukuy) S. S. Ying, Col. III Indig, Orch. Taiwan 1(2): 439. 1977.

Plant 17-33cm tall. Pseudobulbs 7-12 x 0.9-1.3 cm, narrowly fusiform. Leaves 2-5, 11-23 x 2.8-4cm, narrowly obovate-elliptic, plicate, petiolate, acute; leaf base sheath like, 0.6-7cm long; bladeless sheaths green at first, later scarious and fibrous. Inflorescence erect, 4 to 7-flowered; peduncle 2.1-4cm long, sheathed; sheaths overlapping, boat-shaped, acute; rachis 5-8cm long; floral bracts 0.7-1.6cm long, lanceolate, boat shaped, acute. Flowers 3.9-4.5 cm across; sepals and petals white to apple-green, centrally striped with maroon, lip white, pale green or yellow, red-shaped, callus white; pedicellate-ovary 2.2-2.8cm long. Sepals similar, 1.8-2.7 x 0.4-0.7cm, narrowly oblong to obovate, acute to apiculate, erect. Petals 1.7-2.1 x 0.6-0.7cm, oblong to narrowly elliptic, acute to apiculate. Lip 3-lobed, 1.4-1.7x0.8-1.3 cm, minutely papillose; lateral lobes narrow, rounded; mid-lobe 0.5-1 x 0.5-1.2cm, ovate, obtuse, recurved at apex; callus 2-ridged, convergent towards base of the mid-lobe. Column 1-1.2cm long, slender, curved, winged. Anther quadrate; Pollinia obliquely ovoid.

Voucher specimen: [Rajendra et al 0796]; Habitat: Terrestrial; Altitudinal ranges: 350-2400m; Date of collection: 25 March 2009; Flowering: March-April; Status: Rare; Local distribution within Darjeeling: Forest areas in Algarah, Majitar - Kalimpong sub-division; Latpanjar - Kurseong sub-division; General distribution: Nepal, N. India, China, Taiwan, Japan, Myanmar, Indo-China to Malaysia, Java, Sumatra and Borneo.

Fig. 11. Cymbidium lowianum.

10. Cymbidium lowianum (Rchb. f.) Rchb. f. in Gard. Chron., n.s., 11; 332, 1879. (Fig. 11)

Plant perennial herbs, 41-68cm. Pseudobulbs 12-13 x 5-6cm, bilaterally flattened. Leaves 6-9, 50-90 x 3.5-4cm, linear-oblong, sheathing at base. Scapes suberect, longer than the leaves. Inflorescence 30-40 flowered racemes. Flowers 8-10cm, in diam. Sepals similar, dorsal sepal 5.9-6.2 x 1.9-2.2cm, lanceolate, ovate; lateral sepals 5.2-5.5 x 1.5-1.8cm, ovate-elliptic, slightly falcate; Petals 5.3-5.7 x 1.3-1.7cm, lanceolate, ovate. Lip 3-lobed, 3.4-3.7 x 1.5-1.8cm. upper margin of epichile is blackish dark coloured and at the claw red dotted marks. pedicellate-ovary 5-5.5 x 0.5-0.7cm. Sepals and petals green narrowly obovate. Lip 3-lobed, yellowish to white; mid lobe cordate, with a V-shaped red patch; callus ridges 2, white. Column 2.9-3.3 x 0.9-1cm, winged, yellow. lower half of inner side possess red dotted marks. Anther 0.6 x 0.5cm, yellow. Pollinia 4 in 2 bundles, 2 are smaller than others.

Voucher specimen: [Rajendra et al 1094]; Habitat: Epiphytic; Altitudinal ranges: 1400-2800m; Date of collection: 25 March 2010; Flowering: March-May; Status: Rare; Local distribution within Darjeeling: Forest areas in Todey, Neora Valley - Kalimpong sub-division; Takdah - Darjeeling sub-division; General distribution: N.E. India.

Fig. 12. Cymbidium mastersii.

11. Cymbidium mastersii Griff. Ex lindl. In Edwards's Bot. Reg. 31: t. 50. 1845. (Fig. 12)

Plant 28-39cm tall. Pseudobulbs 8-11cm long, stem-like, surrounded by leaf sheaths. Leaves 10-14, apical from pseudobulb, distichous, narrowly oblong, apex acute, unequally 2-lobed, mucronate, 22-51 x 1.4-1.7cm; leaf bases sheathing, 4-8cm long. Inflorescence densely 3 to 8 flowered, curved to pendent; peduncle 14-23cm long, suberect, sheathed; sheaths 15-19 cm long, 6-8, boat-shaped to cylindric; rachis 5-15cm long; floral bracts triangular, acute, 4-7mm long. Flowers fragrant, 5.2-5.8cm across, white or pale pink, lip with a yellow patch at base, callus bright yellow, column white to pale green; pedicellate-ovary 2.9-3.4cm long. Sepals similar, narrowly obovate, acute, concave; dorsal sepal 4.7-5.3 x 0.8-1cm; lateral sepals 5-5.4 x 0.9-1.1cm, weakily falcate. Petals narrowly oblong to obovate, weakily falcate, porrect, 4.5-4.9 x 0.5-0.6cm. Lip 4.5-4.8 x 2.1-2.5cm, 3-lobed, elongate, adnate to the column base; lateral lobes broad, clasping the column, puberulent, broadly rounded to subacute, margins fringed, 1-1.2cm; mid-lobe small, ovate, rounded or mucronate, porrect, puberulent, margins undulate, 1-1.3 x 1-1.3cm; callus long, 2-ridged. Column slender, narrowly winged, 3.5-3.9cm long. Anther ca 4 x 3mm; Pollinia clavate.

Voucher specimen: [Rajendra et al 1773]; Habitat: Epiphytic rarely lithophytic; Altitudinal ranges: 1950-2600m; Date of collection: 13 December 2011; Flowering: October-December; Status: Threatened; Local distribution within Darjeeling: Forest areas in Kaffer, Neora Valley - Kalimpong sub-division; Lopchu - Darjeeling sub-division; General distribution: N.E. India, Myanmar, China and Thailand.

Fig. 13. Cymbidium bicolor.

12. Cymbidium bicolor Lindl. Gen Sp. Orchid. Pl: 164. 1833. (Fig. 13)

Plant 24-57cm tall. Pseudobulbs narrowly ovoid, enclosed in leaf bases; bladeless sheaths 4 or 5, becoming scarious-fibrous with age, ca. 11cm long. Leaves 5-6, 32-72 x 2.4-3.9cm, narrowly oblong, obtuse, stiff, arching; leaf base 3-12cm long. Inflorescence arching to pendent, 10 to 21-flowered; peduncle 2-12cm long, sheathed; sheaths 5, overlapping, boat shaped, spreading, 3.5-5.5 cm long; rachis 8-33 cm long; floral bracts 1.5-4.5mm long, triangular. Flowers 2.5-4.5cm across, scented; sepals and petals pale yellow-cream, striped maroon-brown, lip white-cream with a pale yellow patch at base, mottled with maroon to purple brown, callus cream-yellow, column cream; pedicellate-ovary 2-2.6 cm long. Sepals similar, 1.8-2.2 x 0.5-0.7cm, narrowly oblong to obovate-oblong, obtuse to subacute, erect to spreading. Petals 1.7-2 x 0.5-0.7cm, narrowly oblong-elliptic, spreading. Lip 3-lobed, 1.6-1.8 x 0.9-1.5cm, saccate at base, papillose to shortly pubescent; lateral lobes erect, obtuse, porrect to recurved; mid-lobe 5.2-8.7 x 6-9.6mm, broadly elliptic, rounded, mucronate at apex; callus 2-ridged, entire, minutely papillose-pubescent. Column 1-1.2cm long, curved, winged at apex; foot short. Anther 3x2mm. Pollinia 2, 0.2 x 0.1cm, yellow.

Voucher specimen: [Rajendra et al 0816]; Habitat: Epiphytic; Altitudinal ranges: 300-1500 m; Date of collection: 17 April 2009; Flowering: April-June; Status: Frequent; Local distribution within Darjeeling: Samalbong-Sinjee, Suruk - Kalimpong sub-division; Latpanjar forest - Kurseong sub-division; General distribution: N. India, Nepal, Myanmar, China and Indo China.

Results and Discussion

Fig. 14. Present ecological status of Cymbidium species in Darjeeling Himalaya of India.

During the field survey conducted in the study area, 12 species of Cymbidium orchids were found to occur in Darjeeling Himalaya. The detailed list of these species along with their botanical names, habitat, place of occurrence, altitudinal range of the availability, flowering and fruiting time and current ecological status are presented. In the present investigation, the study of ecological studies of these 12 species following the method Raunkiaer's Ecological Statitistics given by Raunkiaer, (1934) and for Cymbidium (epiphytic), representative quadrate plots of 10m x 10m for epiphytic and 5m x 5m for terrestrial species were laid down in the species habitat rich field revealed that 5 species viz., Cymbidium dayanum, Cym. erythraeum, Cym. lancifolium, Cym. elegans var. elegans (Syn. Cym. longifolium), Cym. lowianum are rare. There were two species Cym. hookerianum and Cym. mastersii which have been placed under threatened category. There were two species viz., Cym. aloifolium and Cym. cochleare that were found sparsely and three species viz., Cym. bicolor, Cym. devonianum, Cym. iridioides, that were found infrequently in the study areas (Fig. 14).

The above ecological status is based on the finding during the survey and it is proposed that all 12 species of Cymbidium available in Darjeeling Himalaya may be placed under these categories as proposed above which is based on the findings following ecological status analysis given by Raunkiaer (1934). During the survey, it was observed that, at almost the year round, some members of the studied genus are in flower. Cym. hookerianum, Cym. lancifolium and Cym. lowianum flower during March to May; Cym. bicolor during April to June; Cym. aloifolium and Cym. devonianum flower during April-July; Cym. erythraeum and Cym. dayanum during August to November; Cym. cochleare, Cym. iridioides, Cym. longifolium, Cym. mastersii flower during October to December. There species were found at as low as 200m at Sevoke forest area near Siliguri to as high as 2800m at Neora Valley forest. They have a wide range of adaptation in the region.

Conclusions

Immediate steps need to be taken for the conservation of these species before they disappear forever, and this is especially the case for the species which are sparse, rare and threatened. Cymbidium longifolium, Cym. lowianum, Cym. hookerianum, Cym. erythraeum and Cym. mastersii are found in the planted condition at home gardens of local villagers in the region. The ever increasing population needs space which is acquired by clearing forest land and expansion of cultivable land for cultivation.

Frequent landslides, forest fires, deforestation for other developmental projects, the felling of old epiphytic host trees for timber and fire wood collection, and indiscriminate collection by the paid agents of floral nurseries businessmen for export and home decoration are all causing huge losses on this valuable Cymbidium orchid species resource. This has to be considered seriously in order to save them intact in their natural habitats. We are fortunate to have these plants still intact in nature even if many are in the stages of rare and meager distribution. If effective conservation steps are taken immediately, we can save these orchid species germplasms within a targeted time frame.

Acknowledgements

The first author is thankful to the University Grants Commission, New Delhi for awarding the Rajiv Gandhi National Fellowship for higher study leading to Ph.D. in Botany.

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Copyright © 2012 Rajendra Yonzone, D. Lama, R. B. Bhujel, Khyanjeet Gogoi, and Samuel Rai