Culms 20-50 cm. Leaves mostly cauline; blades more than 10 cm, loosely involute to flat. Panicles 15-24 cm; primary branches stiff, lower branches strongly divergent to divaricate, with axillary pulvini, upper branches appressed to ascending, without axillary pulvini, lower nodes associated with 8-18 spikelets. Glumes red or dark at anthesis, fading to stramineous; lower glumes 7-11 mm, 3/4 as long as to equaling the upper glumes; upper glumes 10-15 mm; lemmas 10-13 mm long, narrowing to 0.2-0.3 mm wide near the apex; awns subequal, 20-30 mm long, 0.2-0.3 mm wide at the base. 2n = unknown.

Aristida purpurea var. parishii grows on sandy plains and hills of the southwestern United States and Baja California, Mexico. In many respects it is intermediate between A. purpurea and other species of Aristida with spreading panicle branches, especially A. ternipes var. gentilis. Its spikelets are indistinguishable from those of var. wrightii, but var. parishii frequently has axillary pulvini associated with the lower branches. The two also differ in their phenology: var. parishii flowers from March through May in response to winter rains, whereas var. wrightii flowers from May through October in response to summer rains.

Common Name: Parish's threeawn

Duration: Perennial

Nativity: Native

Lifeform: Graminoid

General: Tufted perennial with thick, stout, erect stems 20-50 cm.

Vegetative: Blades mostly cauline more than 10 cm, loosely involute to flat.

Inflorescence: Panicles narrow 15-24 cm long, reddish when young, the primary branches stiffly spreading, lower branches strongly divergent to divaricate, upper branches appressed or ascending, lower nodes with 8-18 spikelets; glumes red or dark at anthesis, unequal, lower 7-11 mm long, upper 10-15 mm long, lemmas 10-13 mm long, narrowing to apex, awns subequal, 20-30 mm long, minute at base.

Ecology: Found on sandy soils, especially flats from 2,500-5,500 ft (762-1676 m); flowers March-May.

Notes: An intermediate between A. purpurea and A. ternipes var. gentilis, the spikelets of this species identical to var. wrightii but with a different phenology.

Ethnobotany: Unknown

Etymology: Aristida is from the Latin arista for awn, while purpurea is Latin for purple, parishii is named for for the Parish brothers Samuel (1838-1928) and William (1840-1918), both California botanical collectors.

Synonyms: Aristida parishii, A. wrightii var. parishii

Editor: SBuckley, 2010