Estableciendo las prioridades de conservación: la importancia del endemismo y la filogenia en el género de orquídeas del sur de Africa

The southern and south‐central African terrestrial orchid genus Herschelia contains several rare and endangered species. The distribution patterns of the species were assessed and classified into the Rabinowitz rarity categories. The degree of rarity was correlated with habitat types and with the phylogenetic history. Of the 16 species recognized, two are too poorly known to be assessed further. Of the remainder, three species are shown to be “metaspecies,” which can be interpreted as being ancestral to five narrowly endemic species. A. strong correlation between the age of the habitats, the relative age of the species, and the degree of rarity was demonstrated. I review the phylogenetic criteria for prioritizing species for conservation, and I develop a new criterion, the ability of a species to speciate into “new” environments. This suggests that it might be better to conserve metaspecies, which are found in the mountains, rather than the autapomorphic daughter species, which are found in the ephemeral habitats of the lowlands.