Resumen

RAYMUNDEZ U, María B; ESCALA, Marcia  y  XENA DE ENRECH, Nereida. Leaf morphoanatomy as a tool for the definition of species of the genus Hymenocallis Salisb. (Amaryllidaceae.) present in Venezuela. Acta Bot. Venez. [online]. 2005, vol.28, n.2, pp.301-320. ISSN 0084-5906.

The Neotropical genus Hymenocallis Salisb. is known as one of the most problematic genus within the Amaryllidaceae. To define some of its species remains difficult because the limits between intra and interspecific variation are often superposed, thus, the main objective of this investigation was to explore the potential of the foliar morphoanatomy to delimit Venezuelan species. These species are geophytes, with seasonal or persistent foliage; sessile, subsessile or pseudopetiolated leaves; leaf blades are linear, lorate, oblanceolate or ellipsoid; anatomy could be equi- or bifacial. Of the evaluated characters, 22 have been selected as the most informative to form species clusters through a hierarchical clustering analysis, using percent disagreement as distance matrix calculation method and simple linkage as joining rule. Analysis of qualitative characters produced seven discrete groups that correspond to each of the studied species, except one which H. venezuelensis partially clusters Hymenocallis lobata. Based on evaluated morphological and anatomical characters, a vegetative key to separate Venezuelan species is presented.

Palabras clave : Leaf Morphology and Anatomy; Hymenocallis; Systematics; Amaryllidaceae; Venezuela.