Additional chromosome numbers of American Acanthaceae

Original meiotic chromosome counts are presented for 39 species in 15 genera of Acanthaceae from Belize, Costa Pica, Ecuador,;Mexico, Panama, the United States, and Venezuela. These reports include the first counts for 20 species representing 10 genera of the family, including the first chromosome number documented for the genus Poikilacanthus. Counts for 15 species confirm numbers previously reported for them from different sources. New chromosome numbers are reported in two genera, Carlowrightia (n = 17 in C. pectinata) and Justicia (n = 24 in J. galapagana). New chromosome numbers are also reported in two species of Justicia J. comata (n = 28) and J. oerstedii (n = 11). Systematic implications of these chromosome numbers are addressed where appropriate.