DISTRIBUCIÓN DE Heliopsis longipes (Heliantheae: Asteraceae), UN RECURSO ENDÉMICO DEL CENTRO DE MÉXICO DISTRIBUTION OF Heliopsis longipes (Heliantheae: Asteraceae), AN ENDEMIC RESOURCE FROM CENTRAL-MEXICO

H eliopsis longipes is a perennial herb endemic to Sierra de Alvarez and Sierra Gorda in central Mexico. It is a species of major economic importance within its genus, due to the traditional uses of its root. Chemical and pharmacological studies have been performed with H. longipes roots, however recent studies regarding its distribution are lacking. The objective of the current study was to establish and document the geographic distribution and existing ecologic conditions of H. longipes. A review of published works regarding this species, as well as an examination of herbarium specimens has been conducted. Explorations in Sierra de Alvarez and Sierra Gorda were also conducted to locate populations of H. longipes. In each site, the physical and biological factors associated with the population were recorded. Heliopsis. longipes is distributed in the states of San Luis Potosi, Guanajuato and Queretaro, in steep canyons with oak and oak-pine forests and substra- tes of igneous origin, in Sierra de Alvarez and Sierra Gorda.