The grass genera of the world
~ Danthonia, Merxmuellera
Type species: E. rangei (Pilg.) P.M. Peterson & N.P. Barker.
Habit, vegetative morphology. Perennial; caespitose. Culms 12–50 cm high. Leaf blades filiform or linear; narrow; 3.5–30 cm long, 1–3 mm wide; not pseudopetiolate. Ligule a fringe of hairs.
Reproductive organization. Plants bisexual, all with bisexual spikelets; with hermaphrodite florets.
Inflorescence. Inflorescence paniculate; contracted; lanceolate to oblong; non-digitate; spatheate (or embraced by the flag leaf), or espatheate; not comprising partial inflorescences and foliar organs. Spikelets solitary; not secund; pedicellate.
Female-fertile spikelets. Spikelets 9–18 mm long; cuneate; compressed laterally; disarticulating above the glumes; disarticulating between the florets; with conventional internode spacings. Rachilla prolonged beyond the uppermost female-fertile floret; the rachilla extension with incomplete florets, or naked. Hairy callus present (pubescent or pilose).
Glumes two; more or less equal; exceeding the spikelets; long relative to the adjacent lemmas (1.3–1.7 times the length of the lowest lemma); pointed (acute to acuminate); awnless; non-carinate; membranous, lanceolate, similar. Lower glume 1 nerved, or 3 nerved. Upper glume 1 nerved, or 3 nerved. Spikelets with incomplete florets. The incomplete florets distal to the female-fertile florets. The distal incomplete florets merely underdeveloped. Spikelets without proximal incomplete florets.
Female-fertile florets 2–3. Lemmas oblong; chartaceous, decidedly firmer than the glumes; not becoming indurated; incised; 2 lobed; deeply cleft (to about half the lemma length); awned. Awns 1; median; from a sinus; 9–18 mm long, geniculate. Awn bases twisted. Lemmas hairy. The hairs in tufts; in transverse rows (with a transverse row of tufts). Lemmas non-carinate; presumably without a germination flap; 9 nerved. Palea present; relatively long (more or less equalling the lemma). Palea back glabrous, or hairy. Lodicules present; 2; truncate, fleshy; glabrous. Stamens 3.
Fruit, embryo and seedling. Disseminule a free caryopsis. Pericarp fused.
Abaxial leaf blade epidermis. Microhairs absent. Subsidiaries triangular.
Transverse section of leaf blade, physiology. Lamina mid-zone in transverse section almost terete (circular in section). The adaxial channel reduced to a small groove.
C3; XyMS+. Mesophyll with non-radiate chlorenchyma. Midrib not readily distinguishable.
Classification. Watson & Dallwitz (1994): not described separately. Soreng et al. (2015): Chloridoideae; Centropodieae. 2 species (E. papposa, E. rangei).
Distribution, phytogeography, ecology. Namibia and South Africa.
Species of coarse alluvial sands.
References, etc. Morphological/taxonomic: Grassbase (2016).
Special comments. Anatomical data wanting.
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, distributions of character states within any set of taxa, geographical distribution, and classifications. See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., Macfarlane, T.D., and Dallwitz, M.J. 1992 onwards. The grass genera of the world: descriptions, illustrations, identification, and information retrieval; including synonyms, morphology, anatomy, physiology, phytochemistry, cytology, classification, pathogens, world and local distribution, and references. Version: 11th December 2017. delta-intkey.com/grass’.