A Revision of Eragrostis (Eragrostideae, Eleusininae, Poaceae) in Australia

Abstract

Based on characters of gross morphology, a taxonomic revision is presented of the Australian taxa of Eragrostis Wolf, comprising 69 endemic and exotic species distributed in six groups. Seventeen species are proposed as new. Ten taxa are hereby reduced to synonymy. Lectotypes are designated for 11 species. New distribution records include E. atrovirens for Australia, E. schultzii for Western Australia, E. leptocarpa and E. pergracilis for Victoria, E. minor for New South Wales, and E. sterilis for New South Wales and the Northern Territory. Polymorphy and interspecific gradation are inherent problems in the taxonomy of the genus. Also, apparent evolutionary characters such as mode of spikelet disarticulation can be inconsistent and difficult to interpret. Features of the caryopsis relating to 3-dimensional shapes, compression, surface markings, and an adnate or free pericarp are among the most useful characters for identification purposes. Cleistogamy occurs in many species, but is not reflected in spikelet morphology. Eragrostis curvula is recorded as an apomict.