Montana Field Guide

Rhizomatous perennial. Stems erect, 10–40 cm with purple sheaths, tufted. Spikelet 3–8 mm long with 10 to 30 flowers. Scales 2–3 mm long, brown to purple with hyaline margins, the lowest larger, sterile, rounded. Flowers: bristles absent or reduced; stigmas 3. Achenes yellow, honeycombed, obovate, 1–1.5 mm long; tubercle triangular, 0.1–0.2 mm long (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Lesica (2012) treats this species as Eleocharis tenuis (Willd.) Schult. variety borealis (Svenson) Gleason

Eleocharis elliptica - Slender Spikerush
*Life Cycle: Perennial; rhizomatous.
*Stems: 10-14 cm tall.
*Achene: yellow, honeycombed, obovoid, and 1.0-1.5 mm long.
*Scales: longer than the achene, 2-3 mm long.
*Stigma: 3

Eleocharis bella - Delicate Spikerush, SOC
*Life Cycle: Annual; lacks rhizomes.
*Stems: 1-8 cm tall.
*Achene: whitish, honeycombed, obovoid, nearly round in cross-section, 0.5-1.0 mm long.
*Scales: about 1.0 mm long.
*Stigma: 3

Eleocharis ovata - Ovate Spikerush
*Life Cycle: Annual; lacks rhizomes.
*Achene: gray to brown, obovate, lenticular, and about 1.5 mm long.
*Scales: longer than the achene,2-2.5 mm long.
*Stigma: 2

Eleocharis acicularis - Least Spikerush
*Life Cycle: Perennial; rhizomatous.
*Stems: 1-25 cm tall.
*Achene: gray, honeycombed, obovoid, and about 1.0 mm long.
*Scales: longer than the achene, 1.5-2.5 mm long.
*Stigma: 3

Eleocharis rostellata - Least Spikerush, SOC
*Life Cycle: Perennial; tufted.
*Stems: 10-80 cm long, erect or arching and able to root at the tip to form new plants.
*Achene: green-gray, obovoid, and 2-6 mm long.
*Scales: longer than the achene, about 2.0 mm long.
*Stigma: 3

Fens, moist alkaline meadows around ponds, streams; valleys, montane (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).