Family: Poaceae |
Sylvia M. Phillips Plants annual; tufted. Culms to approximately 50 cm, erect or geniculate, not woody. Sheaths open; ligules membranous, ciliate; bladesbroadly linear. Inflorescences terminal, panicles of spikelike branches, exceeding the upper leaves; branches 1.5-10 cm, subdigitate or in whorls along elongate rachises, axes flattened, with imbricate, subsessile spikelets, terminating in a rudimentary spikelet. Spikeletslaterally compressed, with 3-25 florets; disarticulation of the spikelets below the glumes, of the lemmas within the spikelets acropetal, spikelets falling wholly or in part after only a few lemmas have fallen, paleas persistent. Glumes 1-veined, keeled, exceeded by the florets; lemmas 3-veined, strongly keeled, firmly membranous to cartilaginous, glabrous, cuspidate or awn-tipped. Fruits modified caryopses, pericarp hyaline, rupturing at maturity; seeds deeply sulcate, ornamented. x = 9. Name from the Greek akros, at the tip and achne, scale, referring to the inflorescence branches which terminate in an aborted spikelet (Clifford 1996). SELECTED REFERENCES Clifford, H.T.1996. Etymological Dictionary of Grasses, Version 1.0 (CD-ROM). Expert Center for Taxonomic Identification, Amsterdam, The Netherlands; Phillips, S.M. 1995. Flora of Ethiopia and Eritrea, vol. 7 (I. Hedberg and S. Edwards, eds.). National Herbarium, Biology Department, Science Faculty, Addis Ababa University, Addis Ababa, Ethiopia and Department of Systematic Botany, Uppsala University, Uppsala, Sweden. 420 pp. Cope, T.A. Poaceae (1995) Flora of Somalia 4: 149-270 Plants annuals. Ligules membranous with a ciliate fringe. Inflorescences panciles of digitately or racemosely distributed spikelike branches with imbricate spikelets and terminatin in an abortive spikelet. Spikelets with several florets, disarticulating below the glumes, the rachillas and paleas persistent, the lemmas deciduous; lemmas strongly keeled, firmly membranous, glabrous, entire or 2-toothed, each tipped with a stout awn point. Grains ellipsoid, with free pericarps. Acrachne is a genus of three species, all native to the Old World Tropics. One species, Acrachne racemosa, is known from Somaliland and Somalia. It has been collectd in both countries. Global distribution of Acrachne. Note: GBIF records include introduced and cultivated plants. Consequently, the distribution shown often differs from statements about a taxon's native distribution. |