No abstract

No abstract

Original chromosome observations including number for 68 taxa representing 47 genera are reported. Of these, 12 are first reports for species representing ten genera. In nine species multivalent associations (rings or chains) were noted; these were not always accompanied by low pollen stainability. Accessory chromosomes (centric fragments or univalents) were noted in two species.

Chromosome observations, including number, from meiotic cells from 155 collections (most from Chiapas, Mexico) representing 138 species from 76 genera of Compositae provide taxonomically useful information, especially first counts (for Espejoa [n = 9], Gymnolaena [n = 13], and Rojasianthe [n = 19] and for 39 species in other genera) and counts that differ from other reports. Pollen stainabilities do not always correlate with meiotic irregularities.

No abstract