Research Advances on Leaf and Wood Anatomy of Woody Species of a Tamaulipan Thorn Scrub Forest and its Significance in Taxonomy and Drought Resistance

The present paper make a synthesis of a comparative leaf anatomy including leaf surface, leaf lamina, petiole and venation as well as wood anatomy of 30 woody species of a Tamaulipan Thorn Scrub, Northeastern Mexico. The results showed a large variability in anatomical traits of both leaf and wood anatomy. The variations of these anatomical traits could be effectively used in taxonomic delimitation of the species and adaptation of the species to xeric environments. For example the absence or low frequency of stomata on leaf surface, the presence of long palisade cells, and presence of narrow xylem vessels in the wood could be related to adaptation of the species to drought. Besides the species with dense venation and petiole with thick collenchyma and sclerenchyma and large vascular bundle could be well adapted to xeric environments. It is suggested that a comprehensive consideration of leaf anatomy (leaf surface, lamina, petiole and venation) and wood anatomy should be used as a basis of taxonomy and drought resistance.