Brillantaisia P. Beauv .

Brillantaisia P. Beauv. View in CoL

— Thirteen species of Brillantaisia are known from tropical Africa and Madagascar. Chromosome counts of n = 16 have been reported for two of them, B. lamium (Nees) Benth. and B. owariensis P. Beauv. (Mangenot and Mangenot 1958, 1962; the latter species reported as B. nitens Lindau ). Our count of n = 16 for the tropical African B. owariensis ( Fig. 1B, C View FIGURE ) confirms the previous counts for this species.

Brillantaisia pertains to Ruellieae: Hygrophilinae along with one other genus, Hygrophila R. Br. , which contains nearly 100 species. A chromosome number of n = 16 has been reported for six of the 11 species of Hygrophila studied to date ( Tripp et al. 2013; Cordeiro et al. 2017), including species native to Africa (e.g., H. senegalensis (Nees) T. Anders. ; Miege 1962), Asia (e.g., H. polysperma T. Anders. ; Grant 1955), and the New World (e.g., H. costata Nees & T. Nees ; Grant 1955, as H. lacustris (Schltdl. & Cham.) Nees ). An ancestral basic number of x = 16 is possible for both Brillantaisia and the subtribe; however, the diversity of other numbers reported for Hygrophila (summarized by Tripp et al. 2013) reveal possible euploidy based on x = 6 and probable dysploidy as well.