Introduction

Diplostephium is a genus of trees and shrubs, that has ca. 110 species (Ulloa & Jørgensen, 2004). It is distributed on high mountains zones from Venezuela to Chile with the exception of two species in Costa Rica (INBio information system, july 2005) and twelve in the "Sierra Nevada de Santa Marta" (Colombia). It makes part of the high andean forest and the paramo ecosystems. Colombia has the most species with 63, the mayority of them found in the Oriental Cordillera, which has 33 registered species until this moment. Diplostephium is the third most diverse genus on the paramos with 70 species after Pentacalia and Senecio (Luteyn, 1999).

According to Cuatrecasas, Thomas Van der Hammen & Antoine M. Cleff (1986) the genus is an element of Neotropical origin that could have reached the paramos from the souther latitudes of South America; where the primitive arboreal species can be found in the high Andean forest while the most advanced members can be found in the paramos and super-paramos. This reinforces previous theories from Cuatrecasas (1969,) who proposed as atavistic characteristics the morphologies present in the arboreal species of high andean forest. Based on this, Cuatrecasas made an phylogenetic ordination into natural groups or series where the deriveted species are more diverse and are found at high altitudes.