Thomas R. Soderstrom

Tatiana Sendulsky

A review of this genus of seven species is provided with descriptions and illustrations of each. Of these species, four are described as new: O. aquaticum, O. grandajlorum, O. piligerum, and O. seminudum. Two, O. pterigodium and O. versicolor, are already known in the literature, and one, O. succisum, is a new combination. In addition to its short, subequal glumes, remarkable peculiarities of this panicoid genus are the enlarged palea of the lower staminate floret and the chartaceous, dark and shining or sometimes opaque and greenish, upper hermaphrodite floret, both of which are united at maturity.

Revision of the South American Genus Otachyrium (Poaceae, Panicoideae)

Mason E. Hale

Emmet J. Judziewicz

Vicki A. Funk

Patricia G. Palmer

V ; and, West African supplement

A Scanning Electron Microscope Survey of the Epidermis of East African Grasses

Fernando O. Zuloaga

In the present study a number of species originally assigned to Panicum but not fitting well within its boundaries have been examined. Some of the characters that have been used in the past to distinguish genera in the tribe have been re-examined, including type of hilum, spikelet compression, relative length of the glumes, consistency of the upper anthecium and whether crested or not, and carriage of the spikelet relative to the axis. Further characters of taxonomic importance have been revealed by studies made with the scanning electron microscope (SEM) at higher magnifications than previously possible. The results of these studies indicate that several species should be removed from Panicum and transferred to other genera. Accordingly the following changes have been made: P. megastachyum Nees ex Trinius and P. albicomum Swallen & Garcia Barriga have been transferred to Brachiaria, P. glutinosum Swartz and P. villaricense Mez to Homolepis, P. grandifolium Doell to Ichnanthus, P. killipii Hitchcock to Paspalurn, and P. macranthum Trinius to Streptostachys. Panicum arnacites Trinius forms the basis of a new genus, Tatianyx. With these changes in content the descriptions of Homolepis and Streptostachys are emended, two new species-Brachiaria tatianae and Streptostachys ramosa-are described, and the unusual species P. aristellum Doell is characterized and a possible relationship discussed. A chart is presented that compares the characters of the genera covered in the present investigation, P. aristellum and the two new species are illustrated, and SEM photomicrographs of all taxa are included.

Classification of the Outlying Species of New World Panicum (Poaceae: Paniceae)

Thomas R. Soderstrom

About

Books

Join the club