Family: Poaceae |
Plants annual or perennial, tufted, sometimes stoloniferous. Culms 7−90 cm long, geniculately ascending or decumbent, usually rooting at the lower nodes. Leaves: sheaths glabrous; ligules membranous, sometimes with a ciliate fringe, usually truncate; blades linear or lanceolate, flat, bases occasionally rounded or cordate. Inflorescences simple panicles or panicles of spikelike branches, these racemosely or digitally attached to the main axes and with nearly sessile spikelets. Spikelets with 3‐14 florets, ovate, elliptic, or oblong, laterally compressed; disarticulation below the glumes, the spikelets falling intact; glumes shorter than the spikelets, 1−3(−7)‐veined, membranous, persistent, tips usually obtuse to acute, sometimes mucronate, occasionally short‐awned (C. burttii); lemmas 3‐veined, membranous, glabrous, scabridulous or hairy, tips truncate, obtuse, or acute to mucronate, occasionally short‐awned (C. burttii); paleas shorter than the lemmas, two‐keeled, the keels ciliate or glabrous, occasionally extending into awns (C. burttii); stamens 3. Caryopses ellipsoid, ovoid, oblong, or reniform, concavo–convex flattened or trigonous (C. burttii), their surfaces granular or rugose, pericarps free. Peterson et al. (2021) modified the interpretation of Coelachyrum based on their molecular phylogeny, adding to it what had been known as Apochiton burttii (as Coelachyrum burttii). They also transferred Coelachyrum poiflorum to Eleusine poiflora, but it was part of a grade, not the core clade. The transfer has not been accepted by POWO (2022), but it seems appropriate so it is accepted here. The above description has been edited for consistency with other descriptions in OpenHerbarium. T.A. Cope (1995) Coelachyrum (emended). Flora of Somalia 4: 185-186 Plants annual or perennial, sometimes stoloniferous. Leaves: ligules membranous, sometimes ciliate fringed. Inflorescences either simple panicles of spikelets or of spikelike branches of sessile to subsessile spikelets, the branches either subdigitate and terminal or scattered along an elongated axis. Spikelets with 5-16 florets; glumes 1-3-veined; lemmas lightly keeled at first, becoming broadly rounded as the grain expands, sometimes puberulous to villous on the sides but not with long, shaggy hairs, tips obtuse, sometimes mucronate. Grains broadly elliptic to subrotund, strongly flattened; pericarps free. Coelachyrum, as interpreted here, includes four species, three of which grow in Somaliland and Somalia. The description given is based on that in the Flora of Somalia, emended to reflect the treatment of Peterson et al. (2021). The key to species includes Eleusine poiflora, which is included in Coelachyrum in the Flora of Somalila. It differs from the the species of Coelachyrum in having woody stolons and long, shaggy hairs on its lemmas. Key to the species of Coelachyrum in Somaliland and Somalia.
Peterson, P.M., K. Romaschenko, Y. Herrera Arrieta, M.S. Vorontsova (2021) Phylogeny, classification, and biogeography of Afrotrichloris, Apochiton, Coelachyrum, Dinebra, Eleusine, Leptochloa, Schoenefeldia, and a new genus, Schoenefeldiella (Poaceae: Chloridoideae: Cynodonteae: Eleusininae). Journal of Systematics and Evolution July 2021. https://onlinelibrary.wiley.com/doi/full/10.1111/jse.12803. Global distribution of Coelachyrum. Note: GBIF records include introduced and cultivated plants. Consequently, the distribution shown often differs from statements about a taxon's native distribution.
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