Wood anatomy of eight species of Pentacalia (Asteraceae) in Venezuela

Abstract

The family Asteraceae is one of the most diverse in Venezuela. Pentacalia is the genus with the highest number of species in the family and its principal distribution area is in Mérida, Táchira and Trujillo states. In spite of its importance, there are few studies about wood anatomy for Pentacalia. The aim of this research was describe the wood anatomy of eight species of Pentacalia: P. cachacoensis, P. greenmaniana, P. imbricatifolia, P. mason-halei, P. pachypus, P. quirorana, P. reflexa and P. venezuelensis to find useful features for identification. Samples were collected in andean paramos of Mérida and Táchira states and cloudy forest in Mérida state. Samples were prepared using standard procedures of xylem microtechnique and description was made according international association of wood anatomists. Species studied can be separated in two groups according the presence or absence of storied structure and in each group, we found differences in qualitative features and, in some cases, is necessary the separation using quantitative features. Only P. pachypus and P. venezuelensis can not be separated using wood anatomical features.

Keywords

• Engrosamientos espiralados
• estructura estratificada
• taxonomía
• xilema secundario