Cytotaxonomic Observations in Loasaceae Subfamily Loasoideae

The first cytotaxonomic review of Loasaceae subfamily Loasoideae is presented including 14 new chromosome counts. Three genera, Sclerothrix (n = 12), Klaprothia (n = 24), and Kissenia (n = 12), and three species of Loasa (n = 13 and 14), two of Caiophora (n = 8), and one of Blumenbachia (n = 12) are reported for the first time. Eighteen previously reported counts are reviewed and evaluated. The cytotaxonomic evidence shows the subfamily to be composed of two diverse elements: an aneuploid series with small chromosomes-Loasa, Blumenbachia, Kissenia, Sclerothrix (n = 14, 13, 12) with one tetraploid, Klaprothia (n = 24)-and Caiophora (n = 8, 7) with large chromosomes. Specific cytotaxonomic problems concerning the limits of these two elements are outlined.