A new section of Cornus in South and Central America
1996
Murrell, Z.E.
Attempts to delimit South American Cornus species and place them into supraspecific taxa have resulted in considerable confusion. Morphological analysis support the recognition of a single species, Cornus peruviana. Two new locations for C. peruviana are reported from Costa Rica, 1,000 km WNW of the closest populations in Colombia, the first report for C. peruviana in Central America. Contrary to previous reports, trichome structure and distribution on the abaxial leaf surface dose not change in a gradient from northern to southern populations. A diploid chromosome number, 2n = 22, is reported for the first time in the species. Based upon leaf and branch orientation, chromosome number, endocarp architecture, and inflorescence structure, C. peruviana appears to be intermediate between the traditionally recognized subgenera Kraniopsis and Mesomora. Based upon this reinterpretation of relationships, C. peruviana is placed in a new section, Umbellicrania, subgenera Kraniopsis and Mesomora are recognized as sections Thelycrania and Bothrocaryum, respectively, and all three sections are placed within the subgenus Kraniopsis.
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