Field Guide to Intermountain Cyperaceae (excluding Carex) › Eleocharis

Eleocharis bella (Piper) Svenson

Pretty spikerush, Beautiful spikerush, Delicate spikerush

Figure 24

Synonyms:

Eleocharis acicularis (L.) Roemer & Schultes var. bella Piper, E. acicularis (L.) var. minima Torrey ex Britton

Plant habit:

Very slender annual (rarely perennial) 1–7 cm tall, forming small, dense, rounded tufts; rhizomes usually absent; culms ascending or spreading, filiform, four-angled or more-or-less cylindric, furrowed, soft to firm, 1–8 cm tall, 0.2–0.3 mm thick.

Leaves:

Usually solitary, straw-colored, apex acute, tooth absent; upper sheath delicately membranous, slightly inflated distally, often disintegrating.

Involucral bracts:

None.

Spikelets:

3–10 (15) flowered, ovoid to ovoid-oblong, terete, apex acute to obtuse, greenish-red to reddish-brown, 1.5–4 mm long, 0.8–2 mm thick.

Scales:

4–15, 8 per mm of rachilla, oblong-ovate, apex acute to acuminate and slightly recurved, midrib obscure to somewhat keeled, midstripe greenish or pale, its margins variably hyaline and somewhat reddish-brown, 1–1.5 mm long, 0.5–0.7 mm wide; lowest scale with a flower and completely clasping the culm.

Flowers:

Perianth bristles absent; stamens 3, anthers 0.3–0.5 mm; styles trifid.

Achenes:

Obovoid, obscurely 3-angled to nearly terete with 6–10 longitudinal ridges (3 ridges prominent), 2–30 very fine horizontal bars, apex blunt, whitish to pale brown or slightly yellowish, 0.6–0.8 mm long, 0.3–0.4 mm wide; tubercles distinct, short and broad, grayish, 0.1–0.2 mm high, 0.1–0.25 mm wide.

Fruiting: spring—summer.
Habitat and distribution:

Bare, often drying soil along streams, lake shores, and in wet meadows from 100 to 2900 m. Locally common in the western states from Washington and Montana south to California, Arizona, New Mexico, and adjacent Mexico. Intermountain collections are from the Reno area, northeastern Nevada, southeastern Oregon, southwestern and northern Idaho, northeastern and east-central Utah.

Similar species:

Eleocharis bella is easily confused with the closely related E. acicularis, a rhizomatous perennial with scales exceeding 1.5 mm long, apex blunt to acute, anthers and achenes exceeding 0.7 mm in length.

Eleocharis bella: photographs of small terminal spikelets, scales and patterned achenes; the rightmost achene retains a scale. Drawings show the tufted plant and enlarged spikelet and achene.
Figure 24. Eleocharis bella. (A) Inflorescences, (B) scales, (C) achenes: right with scale attached on the dorsal side. Photos: E.G. Hurd. Drawings: J.R. Janish (Hitchcock et al. 1969).

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