Williams J. León HernándezAlejandra HernándezLeixi V. García2026-03-222026-03-222017http://erevistas.saber.ula.ve/index.php/pittieria/article/download/10180/10116https://andeanlibrary.org/handle/123456789/66524A study of xylematic conductive elements in 21 species from Rubiaceae family growing in four life zones in Venezuela: tropical dry forest, tropical wet forest, rainy premontane forest and very wet premontane forest is presented. Studied features in each life zone are porosity, diameter and vessel frequency, intervessel pit diameter, intervessel pit type, vessel length element and presence of traqueids or perforated ray cells. Vulnerability (IV) and mesomorphic (IM) indexes are calculated. Rubiaceae family, in different life zones, shows a xylematic conductive system oriented to security in liquids movement (high vessel frequency, low diameter, minutes o small pits, high grouping vessels), with IV and IM lower to mean value for each life zone studied. IV shows a xeromorphic type in Rubiaceae and only in rainy premontane forest is observed a mesomorphic character.esRubiaceaeForestryAmazon rainforestGeographyBiologyBotanyarticle