Terrestrial Orchids

These are found either on their floor of the forests under dense shade as for eg. Calanthe , Acanthephippium , Eulophia macrostachya , Tainia , Phaius etc. or in open grasslands and meadows like species of Habenaria , Peristylus , Pachystoma , Ipsea , Eulophia nuda etc. Plants of the former category are usually evergreen and have pseudobulbs , which are swollen parts of stems, to store food materials and water.

The second type of terrestrial orchid is the tuberous perennial. Here the tuber remains underground and doemant during the dry season . The tubers exhibit a variety of shapes . They may be one of more in number per plant , globose or ovate, fusiform or finger-shaped . They are starchy and often edible . Medicinal properties have been attributed to them from ancient times. ‘ Salep’ is the boiled , peeled and dried tubers of various orchids like Orchis, Platanthera , Eulophia , Habenaria , etc. It is valued as a restorative and is used in the treatment of phthisis , hemiplegia , paralytic infections, Chronic diarrhea ,diabetes etc.

These tubers send up leafy shoots during the rainy season which produce terminal inflorescence and then die down to the underground tubers-all within six months of the commencement of the wet season. During the dry months , there will not be any sign of them above ground . This is the commonest type of terrestrial orchid in South India and is represented by species of Habenaria , Peristylus , Satyrium , Disperis and Platanthera.

Malaxis and terrestrial species of Liparis also follow the same pattern of development and flowering with the difference that here are no undergrounds tubers but modified stems which remain above ground in a dormant condition during the dry months .

Eulophia nuda and species of Nervilia are also seen above ground only during the wet half of the year. But here the leaf-bearing and the flowering shoots are produced separately , the latter preceding the former . In Geodorum the reverse is the case, flowers being produced after the leafy shoot.