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The grass genera of the world

L. Watson, T.D. Macfarlane, and M.J. Dallwitz

Geochloa H.P. Linder & N.P. Barker

Type species: G. lupulina (L. f.) H.P. Linder & N. P. Barker.

Habit, vegetative morphology. Perennial; caespitose; geophytic. Culms 25–75 cm high; herbaceous; tuberous. Plants without multicellular glands. Leaf blades tough, flat, or rolled; exhibiting multicellular glands abaxially; persistent. Ligule a fringe of hairs (1 to several-rowed).

Reproductive organization. Plants bisexual, all with bisexual spikelets; with hermaphrodite florets. The spikelets hermaphrodite.

Inflorescence. Inflorescence paniculate; open, or contracted (usually with branches shorter than the spikelets); espatheate; not comprising ‘partial inflorescences’ and foliar organs.

Female-fertile spikelets. Spikelets about 7–55 mm long; presumably compressed laterally; disarticulating above the glumes; probably not disarticulating between the florets. Rachilla probably prolonged beyond the uppermost female-fertile floret (despite the Linder et al. 2010 description); the rachilla extension probably with incomplete florets. Hairy callus present (villous). Callus blunt (about as long as the rachilla internode).

Glumes two; more or less equal; about equalling the spikelets to exceeding the spikelets; long relative to the adjacent lemmas; similar. Lower glume about equalling the lowest lemma; 1–5 nerved. Upper glume 1–5 nerved. Spikelets probably with incomplete florets, or with female-fertile florets only. The incomplete florets distal to the female-fertile florets. The distal incomplete florets if present, merely underdeveloped; awned.

Female-fertile florets (2–)3–7. Lemmas not becoming indurated; incised; 2 lobed (these sometimes extended into 2 mm setae); not deeply cleft; awned. Awns 1 (much exceeding the laterl setae); median; from a sinus; non-geniculate; straight, or flexuous. Awn bases twisted, or not twisted. Lemmas hairy. The hairs not in tufts; but the scattered dorsal indumentum sometimes longer towards the apex. Lemmas 9 nerved. Palea present; relatively long (sometimes overtopping the lemma sinus); 2-keeled. Palea back between the keels glabrous to hairy. Palea keels hairy (wwith hair tufts). Lodicules present; 2; fleshy (rhomboid); shortly ciliate (without microhairs); 3-veined. Stamens 3 (?).

Fruit, embryo and seedling. Disseminule a free caryopsis. Fruit obovate; glabrous. Hilum linear, but less than a quarter of the caryopsis length. Embryo large.

Cytology. Chromosome base number, x = of G.decora 48.

Classification. Watson & Dallwitz (1994): Stipoideae. Soreng et al. (2015): Danthonioideae; Danthonieae. 3 species (G. decora, G. lupulina, G. rufa).

Distribution, phytogeography, ecology. Restricted to the South African Cape.

In well drained habitats.

References, etc. Morphological/taxonomic: Linder et al. (2010).

Special comments. Anatomical data wanting.

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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.’.