Anatomy, histochemical localization of lipid secretions, and its phylogenetic implications in Brazilian species of Panicum sect. Lorea (Poaceae: Panicoideae: Paniceae)

VEGA, AS; CASTRO, M.; ZULOAGA, F.O.

ANNALS OF THE MISSOURI BOTANICAL GARDEN

Año: 2007

0026-6493

This paper constitutes the first report of the chemical nature, and histochemical localization of secretions in Brazilian species of Panicum sect. Lorea Zuloaga (Poaceae, Panicoideae, Paniceae); the study also includes an anatomical analysis. Lipid secretions were found in leaf sheaths and ligular regions. Lipids accumulate in specialized epidermal cells, at times surrounding the bases of the macrohairs, and in the mesophyll. Viscous secretions have been previously reported for Panicum vaginiviscosum Renvoize & Zuloaga and P. acicularifolium Renvoize & Zuloaga, species in sect. Lorea that are here analyzed anatomically. Lipid secretions are now also reported for the first time in eight other species of sect. Lorea: P. bahiense Renvoize, P. cipoense Renvoize & Sendulsky, P. chnoodes Trin., P. durifolium Renvoize & Zuloaga, P. euprepes Renvoize, P. molinioides Trin., P. poliophyllum Renvoize & Sendulsky, and P. trinii Kunth.