Resumo

MARTINEZ-CABRERA, Dorismilda; ZAVALA-CHAVEZ, Fernando  e  TERRAZAS, Teresa. Morphometric study of Quercus sartorii and Q. xalapensis (Fagaceae). Rev. Mex. Biodiv. [online]. 2011, vol.82, n.2, pp.551-568. ISSN 2007-8706.

A morphometric study was carried out in order to evaluate morphological variation of Quercus sartorii and Q. xalapensis and to contribute to their taxonomic delimitation. Herbarium specimens and material of 11 populations from Mexico in the states of Hidalgo, San Luis Potosí, Tamaulipas, and Veracruz, including 2 sympatric populations, were studied. Characters from foliar architecture, fruits and anatomical features of periderm and wood were analyzed through multivariate and phenetic methods. Principal component and discriminant analyses showed that fruit characters such as acorn, nut, and cupule diameters contributed to group individuals in their species, the acorn of Q. sartorii being smaller than that of Q. xalapensis. Variation was not attributed to latitude or elevation. The resulted phenogram revealed 2 groups in which individuals grouped in their own species if fruit features were included. In addition to the quantitative characters mentioned, 3 traits of the venation pattern plus 2 anatomical features distinguished the individuals of each species. These differences were maintained in the individuals from sympatric populations, supporting the distinctness of Quercus sartorii and Q. xalapensis.

Palavras-chave : acorn; Mexico; morphological variation; multivariate analyses; venation pattern.