Brillantaisia P. Beauv.

Daniel, Thomas F., 2018, Chromosome Numbers of Some Cultivated Acanthaceae with Notes on Chromosomal Evolution in the Family, Proceedings of the California Academy of Sciences 64 (9), pp. 319-332 : 321

Brillantaisia P. Beauv.

— 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 ) 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.

Figures

FIGURE 1 (upper right). Chromosomes of Acanthaceae in pollen mother cells. A. Dyscho- riste thunbergiiflora, metaphase II (only half of cell shown), n = 15. B. Brillantaisia owariensis, telophase I, n = 16 (with one lagging chromo- some toward “upper” pole). C. Brillantaisia owariensis, metaphase I, n = 16. D. Ruellia ele- gans, diakenesis (showing nucleolus, n), n = 17. E. Crossandra infundibuliformis, metaphase I, n = 19. F. Ruellia dipteracanthus, metaphase I, n = 17. G. Justicia scheidweileri, metaphase I, n = 14. Chromosomes shown in outline only are touching or overlapping other chromosomes. Scale applies to all figures. See Table 1 for voucher information.