Plants tightly cespitose, not rhizomatous. Culms 14-80 cm tall, 0.8-2 mm thick, internodes glabrous or pubescent below the nodes; nodes 3-5, glabrous. Basal sheaths mostly glabrous, sometimes pubescent at the base, flat and ribbonlike with age, margins sometimes hairy distally, hairs adjacent to the ligules 0.5-3 mm; collars glabrous; ligules truncate, abaxial surfaces pubescent, ciliate, cilia as long as or longer than the basal membrane, ligules of basal leaves 0.3-0.8 mm, of upper leaves 0.5-1.5 mm, asymmetric; blades 4-30+ cm long, 1-4.2 mm wide, usually flat and more or less straight, sometimes tightly convolute and arcuate. Panicles 7-15 cm long, 1.5-4 cm wide; branches strongly ascending at maturity, longest branches 1.5-4 cm. Glumes unequal to subequal, narrowly lanceolate, 3-5-veined; lower glumes 9-15 mm long, 0.9-1.2 mm wide; upper glumes 8-15 mm; florets 4.8-6.5 mm long, 0.8-1 mm thick, fusiform, terete; calluses 0.2-0.8 mm, acute; lemmas evenly and densely hairy, hairs 1.5-3.5 mm at midlength, apical hairs 2.5-5 mm; awns 10-35 mm, persistent, once-geniculate, first segment scabrous or strigose, hairs to 0.3 mm, terminal segment straight; paleas 2.5-4.5 mm, 1/2-4/5 times the length of the lemmas, hairy between the veins, hairs often as long as those on the lemmas but not as dense, apices usually rounded, occasionally somewhat pinched; anthers 2.3-4.5 mm, dehiscent, not penicillate. Caryopses 3-6 mm, fusiform. 2n = unknown.
Achnatherum parishii grows from the coastal ranges of California to Nevada and Utah, south to Baja California, Mexico, and to the Grand Canyon in Arizona. It differs from A. coronatum in its once-geniculate awns, more densely pubescent paleas, and generally smaller stature; from A. scribneri in its shorter, blunter calluses and more abundant lemma hairs; and from A. perplexum in having longer hairs on its lemmas.
FNA 2007, USDA
Common Name: little Parish's needlegrass Duration: Perennial Nativity: Native Lifeform: Graminoid General: Tuft-forming perennial bunchgrass to 80 cm tall. The inflorescence to 12 cm long, composed of dense, hairy spikelets. Awns on spikelets each have a single bend; many other Achnatherum species have two bends on each awn. Vegetative: Plants in tight clumps, not rhizomatous, stems 14-35 cm tall, 1-2 mm thick, 3-5 nodes with internodes glabrous or pubescent at the base, basal sheaths flat and ribbonlike as they age, mostly glabrous, ligules 1 mm long, hairs next to ligules to 3 mm long Inflorescence: Panicles 7-12 cm long, 1.5-2.5 cm wide, branches strongly ascending with the longer branches 1.5-4 cm long, glumes subequal to unequal, 3-5 veined, 8-15 mm long, florets 5-6 mm long, lemmas and paleas densely hairy, with palea hairs generally shorter but some as long as hairs on lemmas, awns 1-1.5 cm, anthers 2-4 mm, open spontaneously when ripe, caryopses 3-4 mm long. Ecology: Found on gravel and rocky slopes, desert scrub, and pinyon/juniper woodlands from 900-2700 m. Flowers May-August. Distribution: Arizona, Utah, and Nevada Notes: It is distinguished from A. coronatum by its once-bent awns, its densely pubescent paleas, and its smaller size. It is distinguished from A. scribneri by its shorter calluses and denser lemma hairs, and is distinguished from A. perplexum by its longer lemma hairs. A. parishii ssp depauperatum differs from ssp. Parishii by having basal sheath margins that are glabrous or with distal hairs less than 1 mm long, while ssp parishii-s distal hairs are 1-3 mm long. Subspecies depauperatum also has generally shorter stems at 14-35 cm tall, versus ssp parishii-s height of 20-80 cm. Ethnobotany: Unknown Etymology: Achnatherum means awned scale or awn-scaled and comes from Greek word achne for chaff or glume and ather meaning stalk or barb; Parishii is named after botanical collectors and brothers Samuel Parish (1838-1928)and William Parish (1840-1918), who lived in California and traveled extensively in search of plants. Editor: Lkearsley, 2012