Chromosome Numbers of Some Cultivated Acanthaceae with Notes on Chromosomal Evolution in the Family
Author
Daniel, Thomas F.
Department of Botany, California Academy of Sciences, 55 Music Concourse Drive, San Francisco, CA 94118, USA.
tdaniel@calacademy.org
text
Proceedings of the California Academy of Sciences
2018
2018-03-29
64
9
319
332
journal article
295355
10.5281/zenodo.11066989
f4a111e7-e61a-437c-8be4-99dfa6f20262
0068-547X
11066989
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
).