Parish's Spikerush

Eleocharis parishii is very similar to E. montevidensis, with which it sometimes grows. It differs from E. montevidensis mainly in its narrowly lanceoloid to cylindric spikelets and its floral scale apices not recurved or horizontally wrinkled. Some apparent intermediates occur in regions of sympatry. The floral scales of E. montevidensis are more densely placed on the rachilla.

Plants perennial, mat-forming; rhizomes evident, long, 0.5–1(–2) mm thick, firm, cortex persistent, longer internodes 5–30 mm, scales often fugaceous, 5–10 mm, membranous, not fibrous. Culms terete or cross section elliptic (or rectangular), usually with to 8 blunt ridges when dry, 10–50 cm × 0.2–0.7(–1) mm, soft to firm, spongy. Leaves: distal leaf sheaths persistent, not splitting, mostly proximally dark red, distally red to brown or green, thinly papery to thickly membranous, apex usually red brown, subtruncate to obtuse or subacute, callose, tooth often present on most or all culms, to 1 mm. Spikelets narrowly lanceoloid (to narrowly cylindric), 3–20 × 1.5–2.5 mm, apex acute; proximal scale amplexicaulous, entire; subproximal scale empty or with flower; floral scales appressed or spreading in fruit, 15–40, 3–4 per mm of rachilla, orange brown, midrib regions often greenish, ovate, 2–3 × 1 mm, apex entire, rounded to obtuse in proximal part of spikelet, acute in distal part, carinate, at least in distal part of spikelet. Flowers: perianth bristles 3–7, rarely apparently absent, stramineous to whitish, slender to stout, often unequal, rudimentary to slightly exceeding tubercle; stamens 3; anthers yellow to stramineous, 1.1–2 mm; styles 3-fid, 0.3–0.4 × 0.2–0.3 mm. Achenes falling with scales, yellow-brown or dark brown, ellipsoid or obovoid to obpyriform, compressed-trigonous, angles evident to obscure, rarely prominent, 0.8–1.4 × 0.5–0.7 mm, neck absent to long, smooth or sometimes minutely cancellate at 20–30X. Tubercles whitish, pyramidal, often higher than wide, 0.3–0.4 × 0.25–0.35 mm. 2n = 10.

Ariz., Calif., Kans., Nev., N.Mex., Oreg., Tex., Utah; Mexico.

Fruiting spring–fall.

Fresh to brackish, wet soil or emergent, often drying lakeshores, ponds, streams, springs; 500–2300m.

Eleocharis disciformis Parish; E. montevidensis var. disciformis (Parish) V. E. Grant; E. montevidensis Kunth var. parishii (Britton) V. E. Grant

Eleocharis parishii Britton, Jour. N. Y. Micr. Soc 5:110. 1889.
Eleocharis disciformis Parish, Bull. So. Calif. Acad. 3: 81. 1904. (California.)
Culms slender, striate, 1-3 dm. high, in fascicles from slender, extensively-creeping, reddish rootstocks ; upper sheath brown or reddish below, stramineous above, the brownish apex truncate and toothed; spikelets linear-lanceolate, acute, 1-1.5 cm. long, rather loosely flowered; scales ovate-oblong, somewhat rigid, stramineous with chestnut or dark brown sides, acute to obtuse with a short hyaline tip; style trifid; achene trigonous with a blunt outer angle, often nearly plano-convex, ellipsoid, narrowed at both ends, yellow to light brown, smooth or faintly reticulate under magnification; style-base acute, short-subulate to conic, sessile upon the body (1.0-1.2 mm. long) of the achene or surmounting a constriction at the apex of the achene ; bristles white, 6 or 7, exceeding or shorter than the achene, retrorsely toothed.
Type locality: Agua Caliente, San Diego County, California (Parish). ,„ „, . .
Distribution : In deserts and mountain meadows, California, Oregon, Nevada {Hall), Arizona, New Mexico ; northern Mexico. , , ,, ., T„ T^, T, -r c. 1 o^^ orz

Eleocharis parishii is a species of spikesedge known by the common name Parish's spikerush.

It is native to Northern Mexico, the Southwestern United States (from southwestern Oregon and California east to Kansas and western Texas). It grows in moist and sandy habitats with fresh to brackish water.