Barleria (Balkwill & Balkwill, 1997)

Dominique Champluvier, 2011, New and overlooked Acanthaceae taxa from D. R. Congo, Rwanda and Burundi: (1) the genus Barleria, Plant Ecology and Evolution 144 (1), pp. 82-95 : 82

1. Three vicariant species of section Barleria

– The Katangan novelty B. velutina is closely related, morphologically very similar to B. nyasensis and B. sunzuana which differ mainly by the well developed upper lobes of their corolla, upper lobes which are lacking or extremely reduced in B. velutina . The other differences include spiny bracteoles (‘interpetiolar spines’ of various authors), calyx lobe margins provided with straight stiff-tipped teeth in B. nyasensis and B. sunzuana whereas soft bracteoles and upwards-curved soft-tipped teeth characterize the calyx lobe margins in B. velutina . The ecology and altitude ranges seem also to be different, as indicated below after the lists of the collected specimens of B. nyasensis and B. sunzuana.

B. nyasensis and B. sunzuana were put in sect. Barleria by Balkwill & Balkwill (1997); this section is characterized by simple axillary inflorescences, toothed calyx lobes, corolla lobes in a 2 + 3 configuration, and two fertile stamens with three staminodes. B. velutina can be placed without any doubt in the same section. Another species of that section, B. bremekampii Oberm., although morphologically distant from B. velutina , has also extremely reduced upper corolla lobes (see drawing in Balkwill & Balkwill 1997: 556, B1).