Carbon Metabolism in Epidendrum elongatum

Abstract

Epidendrum elongatum is a terrestrial plant rarely epiphyte of the Orchidaceae family, meassuring up to 1.5 m. It is tipically found in the american tropics, where it grows in a variety of sizes, shapes and flowers colours. In Venezuela is found in slopes covered by grasses in mountanous and hilly regions. It has been reported growing at elevations between 1,100 and 2,100 m.a.s.l. (4;5). Some species belonging to Elongatum genus have been reported as CAM plants (3; 14 20). Mc Williams (1970) working with E.alatum and E. radicans observed that a high percentage of the Epidendrae showed CAM. He related CAM with the more advanced epiphytic genera of the Epidendrae. Neales and Hew (1975) reported that among the orchids, CAM was absent in epiphytic species. In the present work we study some physiological parameters to elucidate the photosynthetic pathway in E. elongatum.