Abstract Detail
Systematics Section / ASPT Cerros-Tlatilpa, Rosa [1], Columbus, J. Travis [1]. New Leaf Anatomical Features In Aristida L.(Gramineae). Aristida is one of three genera in the Subfamily Aristidoideae along with Sartidia and Stipagrostis. Aristida is a relatively large genus with 250-300 species, whereas Sartidia (4 spp.) and Stipagrostis (50 spp.) are smaller. The genus Aristida is an important component of grassy plains and arid lands of the world's tropics and subtropics. Studies of this taxonomically difficult genus have relied primarily on morphology and anatomy. An interesting anatomical and physiological feature of this group is its variation in photosynthetic pathways. A C4 photosynthetic pathway characterizes Aristida and Stipagrostis, while Sartidia exhibits a C3 pathway. We present new insights about the evolutionary relationships within Aristida and its relationship to Sartidia and Stipagrostis. Our studies are based on DNA sequence data, lemma micromorphology, and leaf anatomy. Aristida, Sartidia and Stipagrostis are monophyletic, yet the monophyly of Henrard's sections is not supported. New findings in the structure of vascular bundles and vascular patterns are presented for a South American and southwestern US species.
1 - Rancho Santa Ana Botanical Garden, 1500 North College Avenue, Claremont, California, 91711-3157, USA
Keywords: Poaceae leaf anatomy Aristida Sartidia Stipagrostis.
Presentation Type: Paper Session: 20-12 Location: Cottonwood B (Snowbird Center) Date: Monday, August 2nd, 2004 Time: 4:45 PM Abstract ID:553 |