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We report chromosome counts for 107 samples of Verbesina collected in Ecuador, Mexico, and Venezuela. These counts represent 77 species with 47 of these belonging to species never counted before. Most samples have the hypothesized diploid number for the genus of 2n = 34; a few taxa have 2n = 36; 19 collections are polyploid. Polyploidy was found in a majority of the South American samples counted (13/23); polyploidy was not broadly distributed in samples counted for Mexican species (6/84). We report the first octoploid for a collection of Verbesina, V. pedunculosa from northcentral Mexico at n (4x) = 68. Previously published counts for Verbesina amount to 175 records representing 90 species. Together with the counts we report here, chromosome numbers are now known for 137 species of Verbesina.
Yucca carrii, a new species from the northern Gulf Coastal Prairie of Texas is described. Morphology indicates that Yucca carrii belongs to Section Chaenocarpa (the dry-fruited yuccas). A lack of observed fruit production to date and reduced pollen viability indicates that this species may be of hybrid origin. The sole pollinator, the yucca moth, has not been documented within the species' range; it may be extirpated. Although known from few populations, the wide-ranging distribution of this species along the north Texas coast, ecological niche specificity and morphological distinctiveness indicates this taxon may have a long history in the area and persists by way of vegetative reproduction. It may be vulnerable to extinction and conservation measures are warranted. DNA analyses are needed to determine the origin and relationship of Y. carrii within Yucca L. Examination of the type of Y. tenuistyla Trel. revealed Y. tenuistyla is a nomen confusum that was described from a mixed collection of three yucca species, none of which is Y. carrii.
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