Anatomy of the Muhlenbergia montana Complex (Poaceae)

Abstract

Leaf anatomical data from 13 taxa of the Muhlenbergia montana complex were surveyed, and 18 critical characters were found. Results obtained from the phenetic analysis of anatomical data have given independent data to compare with the morphological, phytogeographical, and flavonoid data (previously reported) in determining the relationships of the species. An anatomical dendogram illustrates a close corroboration. Leaf anatomy clearly supports the recognition of a close relationship among the two taxa-M. virescens and M. quadridentata-as has been suggested in previous reports. Therefore, a change of level is suggested in which M. quadridentata (H.B.K.) Kunth is proposed here as M. virescens (H.B.K.) Kunth ssp. quadridentata (H.B.K.) Herrera (comb. nov.). Approximately 160 species of Muhlenbergia Schreb. are reported by Clayton and Renvoize (1986). The majority of the species are xeromorphic, caespitose forms that grow in steppe or desert climates of the western United States, Mexico, and Central and South America (Pohl, 1969). Members of the genus occur from subarctic North America to southern South America (Pohl, 1969) and show diversity in growth habit, morphology, and ecology. The Kranz syndrome C4 type leaf anatomy is reported *for the genus (Hattersley, 1984), particularly the parenchyma sheath subtype which is the most common and which is found in species occupying the most arid regions (Brown, 1977).