ESTUDIO DE ASPECTOS BIOLÓGICOS Y POBLACIONALES EN RELACIÓN AL ESTADO DE AMENAZA DE Oxycarpha suaedifolia S. BLAKE (ASTERACEAE), ESPECIE ENDÉMICA DE LA PLANICIE XEROFÍTICA COSTERA DEL ESTADO FALCÓN, VENEZUELA

Abstract

Oxycarpha suaedifolia S. Blake (Asteraceae), endemic to Venezuela, with relatively sparse populations and whose biology is poorly understood, such that it is difficult to establish its conservation status. Its distribution covers coastal semiarid zones in Falcón State, surrounding population centers and areas with extreme environmental conditions. To gather the necessary information and establish the possible threat status of this species, we studied its morphology and evaluated variables of reproductive biology, as well as investigating population components and the geographical distribution. These population-based studies were conducted in the field; we employed botanical dissection techniques, using a stereo microscope, and conducted laboratory tests on germination and emergence. The extent of occurrence is 1,562.73 km2 and it occupies an area of 422 km2. O. suaedifolia is a policarpic herb, repent and cespitose, with above and below ground stolons; simple opposite leaves; homogamous capitula, with numerous hermaphroditic and fertile flowers; syngenesious stamens; laterally compressed cypselae, with 10 ribs and pappus with a hard crown, ending in a lateral awn. It produces an average of 62 ovules per inflorescence and 61 healthy cypselae per capitulum, with an average natural reproductive rate of 98.4%. These have an average germination rate of 88.66% and an emergence rate of 3.30%. Applying the IUCN criteria regarding population