Phytologia (January 1996) 80(1)35-39 NOMENCLATURAL COMBINATIONS IN SCHIZACHYRIUM (POACEAE: ANDROPOGONEAE) Joseph K. Wipff Herbarium (BRCH), Botanical Research Center, P.O. Box 6717, Bryan, Texas 77805-6717 U.S.A.
[email protected] ABSTRACT The following nomenclatural combinations in the Poaceae are proposed: Schizachyrium spadiceum (J. Swallen) comb. nov.; and Schizachyrium scoparium (A. Michaux) G. Nash var. stoloniferum (G. Nash) comb, et stat. nov. KEY WORDS: Schizachyrium, Schizachyrium scoparium, Schizachyrium scoparium var. stoloniferum, Schizachyrium spadiceum, Schizachyrium stoloniferum, nomenclature, Poaceae Schizachyrium spadiceum (J. Swallen) J. Wipff, comb. nov. BASIONYM: Andropogon spadiceus J. Swallen, Proceedings of the Biological Society of Washington 56:82 (1943). TYPE MEXICO. Coahuila; Canon de Madera, western side of Sierra de los Guajes, about 4 km east of Rancho Buena Vista, 7 Sept 1941, Robert M. Stewart 1504 (HOLOTYPE: US, accession #154691). Schizachyrium spadiceum, restricted to Coahuila, Mexico and Brewster County, Texas, is the first reported species oi Schizachyrium with a panicle of paired branches. All of the other reported speaes of Schizachyrium have spicate racemes. This should not be surprising since there are species of Andropogon that have spicaie racemes (e.g., A. textilis A. Rendle, A. fastigiatus O. Swartz, and A. gracilis K. Sprengel), and there are also species that may have either spicate racemes or panicles of paired branches (e.g., A. urbanianus A. Hitchcock, A. reedii A. Hitchcock & E. Ekman, and A. kelleri E. Hackel). It appears that too much significance has been placed on the condition of spicate racemes vs. panicles of pnmary branches; more reliable characters can be found in the lower glume of the sessile spikelet, the intemodes of the central axis, and the pedicels (Clayton 1964). Clayton ( 1964) pointed out that the significance attached to spicate racemes probably arose from the value of this character in segregating Schizachyrium Nees von Esenbeck. Excluding the parucles of paired branches, S. spadiceum possesses all of the below mentioned genenc characters that 35
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