A chemotaxonomic and morphological appraisal of Aloe series Purpurascentes, Aloe section Anguialoe and their hybrid, Aloe broomii

Evidence is presented to suggest the hybrid origin of Aloe broomii, with th e one putative parent belonging to Aloe series Purpurascentes and the other a member of Aloe series Anguialoe. A chemotaxonomic and morphological asse ssment is presented for both infrageneric groups and their hypothesised hyb rid. Four of the species belonging to the series Purpurascentes display a c haracteristic leaf exudate profile containing the chemotaxonomic marker mic rostigmin. Aloe gariepensis and A. succotrina lack the diagnostic leaf exud ate compounds. The distinct morphological apomorphies for Aloe section Angu ialoe are supported on the chemical level reinforcing the monophyly of this group. (C) 2001 Elsevier Science Ltd. All rights reserved.