Orchids of Western Ghats Dr. S.K. Jogdand P.G. Dept. of Botany Mrs. K.S.K. College Beed Orchids, one of the beautiful creations of the nature, comprise an unique group of plants. Being one of the largest families of the flowering plants, Orchidaceae constitutes about 7% species of all Angiosperms and nearly 40% of monocotyledons. It is one of the largest and most diversified families of Angiosperms represented by 25,000 to 35,000 species belonging to 600 – 800 genera (Arditti, 1979) distributed in all parts of the world except, perhaps, in the Antarctica (Abraham and Vatsala, 1981). India represents about 1,141 species belonging to 140 genera of orchids with Himalayas as their main home (Kumar and Manilal, 1994). Orchids are perennial herbs and exhibit incredible range of diversity in habit; shape, size, colour and fragrance of flower and its fascination. Orchids are highly evolved among the monocotyledons and also possess evolved flower and seed. The Western Ghats of India, one of the salubrious spots providing vast range of habitats for a good number of orchid species is one of the Hot- Spots of endemic plants of India. It is the second richest and diverse spot as far as orchids are concerned. It harbors 267 species, 3 subspecies, and 2 varieties of orchids belonging to 72 genera of which more than 46% are endemic. Orchidaceae are one of the dominant families in the Western Ghats only next to the Poaceae and Leguminoceae. Among the Monocotyledons, family Orchidaceae is found to be interesting for its Taxonomy, Cytogenetics, Adaptations, and Propagation. During speciation orchids have adapted themselves to various habitats ranging from open grassland to high mountains. To conserve the endemic species a multifaceted approach of study is necessary. A large number of indigenous wild orchids are highly ornamental and are in great demand. No proper steps have been taken to study these orchids for their mass propagation using conventional as well as non-conventional techniques. No studies are performed for their improvement and utilization as ornamental species. Orchids attracted man from its civilization because of exquisite beauty along with so many unique characters of the flower. It has always remained attraction of botanists. THE WESTERN GHATS Conspicuous geographical feature of the peninsula. One of the eight hottest hot spots of world. Salubrious spot providing Palghat vast range of habitats. gap It runs about 1600 km. Straddle the states of Gujarat, Maharashtra, Karnataka, Goa, Tamil Nadu and Kerala. Harbors 4000 species of flowering plants with 50% endemic elements. Second richest and diverse geographic zone of India. Taxonomy of orchids Cronquist (1981) Class- Liliopsida Sub class- Lillidae Order- Orchidales Family- Orchidaceae Growth habits of orchids 1. Terrestrial Orchids: Habenaria, Peristylus, Eulophia, Malaxis 2. Saprophytic Orchids: Epipogium, Choralorhiza 3. Aquatic Orchids: Eulophia ramentacea, Zeuxine strateumatica 4. Epiphytic Orchids: Aerides, Vanda, Rhynchostylis, Dendrobium, Thunia Organs of the orchid plant 1. Root 2. Rhizome 3. Pseudobulb 4. Leaf 5. Inflorescence 6. Flower 7. Fruit 8. Seed Growth patterns of orchids 1. Sympodial type: All terrestrial orchids, Cymbidium, Thunia, Dendrobium, Bulbophyllum, etc. 2. Monopodial Type: Aerides, Vanda, Rhynchostylis, Cottonia 3. Pseudomonopodial (Diapodial) type: Cleisostoma Vegetative propagation 1. Division 2. Back bulbs 3. Cuttings 4. Offsets/ Keikis 5. Air layering Distribution of orchids (Orchid zones of India: Bose et al., 1999) 1. Plains (Sea level to 300m): Acampe praemorsa, Pholidota pallida 2. Tropical zone (300-900m): Rhynchostylis retusa, Nervilia aragoana 3. Sub tropical zone (900-1800m): Dendrobium, Habenaria, Thunia 4. Temperate zone (1800-3500m): Aerides, Arachnis, Cymbidium 5. Alpine zone (3500-5000m): Bulbophyllum rretusisculum, Habenaria cumminsiana, Nervilia macroglossa, Classification of orchids Bentham and Hooker (1883) Tribe 1. Epidendreae: Anther one, terminal, deciduous; Pollinia waxy, 1 - 4, held together by a viscid appendage (Nine subtribes). Tribe 2. Vandeae: Anther one; Pollinia Waxy, 2 or 4 in superimposed pairs, attached to a gland or part of the rostellum which is carried away when pollinia is removed (Eight subtribes). Tribe 3. Neottieae: Anther one, terminal, with 2 distinct parallel cells; Pollinia granular, powdery or sectile (Six subtribes). Tribe 4. Ophrydeae: Anther one, posterior; Pollinia solitary, granular, produced into caudicles attached to a gland or to the rostellum. Terrestrial (Six Sub tribes). Tribe 5. Cypripedieae: Anthers 2, at the sides of the rostellum, with parallel contiguous cells; Pollen granulose; Lip inflated, shoe shaped. Economic Importance of orchids 1. Orchids as botanicals 2. Orchid as spice 3. Orchids as medicine 4. Orchids as food 5. Orchids as cultural activities 6. Orchids as ornamentals A. COLLECTION, IDENTIFICATION, DISTRIBUTION AND PRESENT STATUS OF ORCHID SPECIES FROM STUDY AREA The floristic account of Orchidaceae Established an Orchidarium 44 Tahsils, 41 genera and 109 species 52 epiphytic and 57 terrestrial species Sr. Orchid species reported in Total No. of Endemic No. orchid orchid species species 1 India 1141 344 2 Peninsular India 322 136 3 Western Ghats 267 84 4 Study area of present work 109 41 5 Cultivated in Botanic Garden 74 32 Comparative account of endemic species of orchids 1141 No. ofspecies No. 344 322 267 136 109 84 74 41 32 Species distribution in various orchid genera ADAPTATIONS IN ORCHIDS 35 Flowering calendar of orchids Epiphytic species 30 Terrestrial species 25 20 15 10 No. of species in flower in species of No. 5 0 April May June July March January August October February November September December Through out year Month S = Sympodial (79 species) M = Monopodial (18 species) P = Pseudomonopodial/ Diapodial (12 species) Total = 109 species. Adaptations in Flowers: i) Epiphytic orchids produce colourful and fragrant flowers as compared to terrestrial ones. ii) Orchids like Habenaria grandifloriformis, H. crinifera, H. longicorniculata and Pecteilis gigantea glitter during night and attract nocturnal insects like Hock moths. iii) White flowered terrestrial orchids are always sweet scented and night blooming and dull coloured flowers of terrestrial orchids are foul scented. In Habenaria gibsoni, H. foetida and H. foliosa stratification of insects is based on odour of flowers. iv) The labellum shows great diversity in size, shape, colour and form. The labellum might play important role in the stratification of insect pollinators e.g. pollination biology of Cottonia peduncularis (Yadav, 1995). v) To avoid the self pollination in orchids the third stigma is modified in to the partition wall called rostellum. Diversity in Labellum Dendrobium crepidatum Aerides dalzelliana Aerides ringens Habenaria grandifloriformis Adaptations in Seeds: i) All orchids produce millions of minute seeds in the capsules. Production of minute but numerous and very buoyant seeds seems to be an adaptation against the selection by chance in nature. (Wright, 1931). ii) There are equal chances of survival or death of fungus and seed as well as symbiotic equilibrium Bernard (1904). iii) Orchid seeds being small in size and light in weight are adapted for wind and water dispersal. a) Buoyancy of orchid seeds - seed/embryo volume ratio-seed dispersal- distribution of the species. b) Species with highly buoyant seeds are widely distributed. c) Species with less buoyant seeds but widely distributed: they might have great adaptive amplitude to diverse habitats. d) Orchids with highly buoyant seeds but having narrow range of distribution because of their habitat specificity. Seed/ Embryo volume ratio Seed/ Seed/ Sr. Range of Sr. Range of Orchid species embryo Orchid species embryo No. Distribution* No. Distribution* volume ratio volume ratio 1 Acampe praemorsa Blatt. & McC 1.304 Narrow 17 Geodorum densiflorum Schltr. 10.396 Wide 2 Aerides crispum Lindl. 1.153 Narrow 18 Lusia zeylanica Lind. 1.365 Wide 3 Aerides maculosum Lindl. 1.196 Narrow 19 Malaxis rheedei Sant. & Kap. 2.980 Wide 4 Bulbophylum fimbriatum Rich 1.809 Narrow 20 Oberonia brachyphylla Blatt. & McC. 1.421 Narrow 5 Cottonia penducularis Reich. 1.342 Narrow 21 Oberonia falconeri Hook. F. 1.331 Wide 6 Cymbidium aloifolium Bl. 4.511 Wide 22 Oberonia recurva Lindl. 4.057 Wide 7 Dendrobium aqueum Lindl. 1.397 Narrow 23 Oberonia wightiana Lindl. 3.076 Wide 8 Dendrobium barbatulum Wt. 3.022 Narrow 24 Peristylus goodyeroides Lidl. 4.053 Wide 9 Dendrobium crepidatum Lindl. 2.210 Wide 25 Pholidota pallida Lind. 3.215 Wide 10 Dendrobium lawianum. 1.943 Wide 26 Polystachya concreta Hook. f. 1.387 Wide 11 Dendrobium macrostachyum 1.345 Narrow 27 Rhynchostylis retusa Bl. 1.041 Wide 12 Dendrobium microbulbus 1.345 Narrow 28 Thunia venosa Rolfe. 2.264 Narrow Blatt. & McC. 29 Vanda testacea Lind. 1.139 Wide 13 Dendrobium nanum J.D.Hook 3.208 Narrow 30 Zeuxine gracilis Bl. 3.989 Wide 14 Dendrobium ovatum Kranz. 2.645 Narrow 31 Zeuxine longilabris Bth. 4.097 Wide 15 Eria reticosa Wt. 1.982 Wide 32 Zeuxine strateumatica Schltr. 2.598 Wide 16 Eulophia nuda Hook. f. 8.221 Wide * Kumar and Manilal (1994) Viability of orchid seeds in mature fruit Sr. Orchid species Viability (%) Sr. Orchid species Viability (%) 1 Acampe praemorsa Blatt. & McC 99.37 17 Geodorum densiflorum Schltr. 100 2 Aerides crispum Lindl. 94.50 18 Lusia zeylanica Lindl. 78.46 3 Aerides maculosum Lindl. 80.48 19 Malaxis rheedei Sant. & Kap. 100 4 Bulbophylum fimbriatum Rich 77.27 20 Oberonia brachyphylla Blatt. & McC. 79.77 5 Cottonia penducularis Reich. 99.09 21 Oberonia falconeri Hook. F. 100 6 Cymbidium aloifolium Bl. 100 22 Oberonia recurva Lindl. 84.26 7 Dendrobium aqueum Lindl. 68.25 23 Oberonia wightiana Lindl. 67.61 8 Dendrobium barbatulum Wt. 100 24 Peristylus goodyeroides Lidl. 75.60 9 Dendrobium crepidatum Lindl. 92.85 25 Pholidota pallida Lind. 78.94 10 Dendrobium lawianum. 90.69 26 Polystachya concreta Hook. f. 94.33 11 Dendrobium macrostachyum 94.73 27 Rhynchostylis retusa Bl. 88.70 12 Dendrobium microbulbon 83.87 28 Thunia venosa Rolfe. 82.60 Blatt. & McC.