摘要：The geographic distribution of the species of Datura in Mexico was analyzed using numerical analysis ofnatural populations documented by herbarium specimens. A map of Mexico was divided into 239, 1° x 1° squares(latitude and longitude) which were used as sampling geographical units and in which the presence or absence ofeach species of Datura was recorded. Multivariate procedures were applied: a), TWINSPAN classification to defineDatura´s main distribution areas; b), Detrended Correspondence Analysis (DCA) to define Datura´s main distributiongradients, and c), Canonical Correspondence Analysis (CCA) to relate distribution patterns with geographical andclimatic factors. Species of Datura were found in 69% (165) of the squares. TWINSPAN defined 14 groups which,when associated with Mexico’s biogeographic provinces, were concentrated in the northwestern Mexican provincesas well as in the Altiplano Norte and Altiplano Sur and the Sierra Madre Occidental. DCA indicated that Datura’smain distribution patterns are explained by 3 principal gradients: altitude, humidity, and latitude. The CCA identifiedlongitude, precipitation of the driest quarter, altitude, and average temperature of the warmest quarter as the mostimportant variables affecting Datura´s distribution patterns. The Depresión del Balsas region of central Mexico is thearea with greatest species richness of Datura.
关键词：Biología; Botánica; Biogeografía;clustering; Datura; geographic distribution; Mexico; ordination; biogeographic provinces
