Amelichloa

Plants perennial; cespitose. Culms erect, with 2-3 nodes, not branching at the upper nodes; basal branching intravaginal; prophylls concealed by the leaf sheaths, winged over the keels, apices bifid, teeth 0.5-3.5 mm. Leaves mostly basal; sheaths open, smooth, glabrous; cleistogenes often present, spikelets of cleistogenes 0.5-1 mm long, with thin glumes shorter than the florets, florets unawned or with reduced awns; auricles absent; ligules scarious, rounded to acute, ciliate; blades stiff, involute, apices stiff, brown, sharply pointed, blades of the flag leaves 5-13 cm long, bases similar in width to the top of the sheaths. Inflorescences panicles, the main panicle terminal, apparently wholly chasmogamous. Spikelets with 1 floret; disarticulation above the glumes, beneath the floret. Glumes exceeding the floret, acute to acuminate, 1-5-veined; florets fusiform, terete; calluses antrorsely strigose, blunt; lemmas pubescent, often more densely and/or more persistently so over the midvein and lateral veins, hairs on the proximal portion about 0.7-2 mm, hairs on the distal portion often longer; crowns not developed; awns once- or twice-geniculate, scabrous, persistent; paleas 3/4 as long as to almost equaling the lemmas, flat, hairy, hairs 0.2-1 mm, veins terminating at or near the apices, apices similar in texture to the body; lodicules 3; anthers 3, anthers sometimes all of equal size and more than 2 mm, sometimes 1 longer than 2 mm and 2 much shorter, sometimes all shorter than 2 mm; ovaries glabrous; styles with 2 branches, united at the base, stigmas plumose. Caryopses obovoid, with 3 smooth, longitudinal ribs at maturity, stylar bases 1-2 mm, persistent, sometimes eccentric; hila linear, about as long as the caryopses. x = unknown.

Discussion

Amelichloa includes five species, four of which are South American. The fifth species, A. clandestina, grows in northern Mexico. Two species are established in the Flora region. A third species, A. caudata. was found on ballast dumps near Portland, Oregon, at the turn of the twentieth century; it is not established in the region.Cattle avoid species of Amelichloa because of their sharply pointed leaves. This means that any of the species could become a serious problem in rangelands. Mowing favors their establishment and spread because it does not eliminate, and may disperse, the cleistogenes. The species are eaten by goats.

Selected References

Caro, J.A. and E. Sanchez. 1971. La identidad de Stipa brachychaeta Godron, S. caudata Trinius y S. bertrandii Philippi. Darwinia 16:637-653

Torres, M.A. 1993. Revision del genero Stipa (Poaceae) en la Provincia de Buenos Aires. Monografia 12. Comision de Investigaciones Cientificas, Provincia de Buenos Aires, La Plata, Argentina. 62 pp.

Lower Taxa

Amelichloa brachychaeta, Amelichloa caudata, Amelichloa clandestina

Key

1	Mature caryopses with inclined, eccentric stylar bases; lemmas glabrous or hairy between the lateral and marginal veins, glabrous between the midvein and the lateral vein, even at the base	Amelichloa caudata
1	Mature caryopses with erect, usually centric stylar bases; proximal 1/2 of the lemmas pubescent between the lateral and marginal veins, at least initially, usually also between the midvein and lateral veins.	> 2
2	Florets 4-5.5 mm long; ligules 0.2-0.6 mm long; anthers 2-3 mm long	Amelichloa brachychaeta
2	Florets 5.5-8 mm long; ligules 0.5-1.5 mm long; anthers 3-4 mm long	Amelichloa clandestina