Justicia L

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 : 324

Justicia L .

— Daniel (2000a) discussed chromosome numbers, as then known, in this rich (ca. 700 species) and widely distributed genus. Kiel et al. (2017, 2018) provided a detailed phylogenetic framework for Justicia and its relatives and discussed chromosome numbers in lineages treated therein. Our approximate count of n = ca. 14 for a wild-collected plant of J. fulvicoma Schltdl. & Cham. , a species endemic to Mexico, generally agrees with the two previous counts of n = 14 for this species, one cultivated (e.g., Daniel and Chuang 1998) and the other wild-collected ( Daniel et al. 1990). This same number is common (but not exclusive) among the other sampled members of the “Brandegeeana clade” to which J. fulvicoma pertains ( Kiel et al. 2018). Our count of n = 14 for the Brazilian J. scheidweileri V.A.W. Graham ( Fig. 1G ) is the first count for the species, which is often referred to as Porphyrocoma pohliana (Nees) Lindau in older literature, and was not included in the sampling by Kiel et al. (2017, 2018). A haploid complement of 14 is also the most common chromosome number reported for the more than 100 species of the genus studied to date (cf. Daniel 2000 for a frequency histogram of chromosome numbers reported for the genus). Based on the diversity of chromosome numbers reported for this large and nonmonophyletic, as currently treated, genus (i.e., n = 7, 9–18, 20, 22–31, 34; Daniel 2000a, 2006; Daniel et al. 2000), it is ikely that both polyploidy and dysploidy have played roles in the evolution of these taxa, and that a knowledge of chromosomal data will be useful in unraveling the taxonomy of justicioids. An ancestral basic number of x = 7 has been proposed for Justicia (e.g., Piovano and Bernardello 1991; Daniel 2000a).

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.