1. Introduction
Brazilian “campos rupestres” vegetation (rupestrian field or rocky field) occurs in mountains above 900 m altitude, in shallow and sandy soils with a high degree of rocky outcropping. This vegetation type is notable for its species richness and for its high number of endemic species (Joly, 1970 and Giulietti and Pirani, 1988). Most of the endemic taxa are restricted to isolated mountains or smaller ranges that make up part of the Espinhaço Range (Alves and Kolbek, 1994), a mountain chain extending approximately 1000 km in a North–South direction in eastern Brazil.