The taxonomic position of C3 and C4 Alloteropsis semialata (Poaceae) in southern Africa

Abstract

Alloteropsis semialata (R. Br.) Hitchc. sensu Chippindall (1955) and Clayton (in press) is the only known grass species in which elements with both non-Kranz and Kranz leaf blade anatomy, and therefore with C₃ and C₄ photosynthetic pathways are included. In the past, two taxa had been recognized, but the characters used to separate them were found to be unreliable, so they were united. However, study of voucher specimens for anatomical and physiological work has shown that C₃ and C₄ taxa may be separated on the basis of morphological characters that differ from those considered in the past. Therefore, two taxa are again recognized, this time at the rank of subspecies, and the name Alloteropsis semialata subsp. eckloniana (Nees) Gibbs Russell stat. nov. is published.