A monograph of Trichanthecium, a new genus segregated from Panicum (Poaceae: Panicoideae: Paniceae)

F.O. ZULOAGA; A. SCATAGLINI; MORRONE, O.

Systematic Botany Monographs

Ohio Wesleyan University

Lugar: Delaware, Ohio; Año: 2011 vol. 94 p. 1 - 98

0737-8211

Abstract. Taxonomic features of species of Panicum, previously classified in section Parvifolia and Verruculosa, are reviewed and compared with those of other taxa in the Paniceae. The new genus Trichiochlaena is proposed on the basis of shared morphological characters, such as plants with membranous ligules, inflorescences lax and open, spikelets ellipsoid to obovoid, pilose or glabrous, lower glume nearly ½ to as long as the spikelet, (1-)3-nerved, upper glume 3-5 nerved, and upper anthecium indurate with globose or elongated bicellular microhairs and simple papillae all over its surface. These morphological characteristics were confirmed with molecular phylogenetic studies, analyzing chloroplast ndhF and rpoA sequences. As a result, a total of 38 American and African species are considered within the genus Trichiochlaena, and therefore a total of 38 new combinations are proposed. The new genus is compared  with other genera of the Paniceae. Lectotypes are designated for  Isachne trochainii A. Camus, Panicum carannasense Mez, P. cyanescens var. rigidiusculum Döll, Panicum frederici Rendle, P. helobium Mez ex Henrard, P. ianthum Stapf, P. natalense Hochst., P. pubiglume Stapf,  P. stenocladium Trin., and P. schwackeanum Mez.   Keywords: Poaceae, Grasses, Panicum, Trichiochlaena, phylogeny, taxonomy.