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Montana Field Guide

Montana Field Guides

Ovate Spikerush - Eleocharis ovata
Other Names:  Eleocharis obtusa var. ovata

Native Species

Global Rank: G5
State Rank: SNR
C-value: 6

Agency Status


External Links

General Description
Fibrous-rooted annual. Stems ascending to erect, 4–20 cm, tufted. Spikelet 4–10 mm long with numerous flowers. Scales brown with hyaline margins and a lighter midrib, 2–2.5 mm long. Flowers: bristles 0 to 7, equaling or exceeding the achene; stigmas usually 2. Achenes grey to brown, smooth, obovate, lenticular, ca. 1.5 mm long with a broad, low tubercle 0.1–0.2 mm high (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Diagnostic Characteristics
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 - Ovate 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 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 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 rostellata - Beaked 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

Species Range

Range Comments
Circumboreal south to AZ, OK, TN and VA (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Observations in Montana Natural Heritage Program Database
Number of Observations: 2

(Click on the following maps and charts to see full sized version) Map Help and Descriptions
Relative Density



(Observations spanning multiple months or years are excluded from time charts)

Vernally wet to shallowly submersed soil on the margins of ponds, lakes, sloughs; valleys (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

  • Literature Cited AboveLegend:   View Online Publication
    • Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.
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Citation for data on this website:
Ovate Spikerush — Eleocharis ovata.  Montana Field Guide.  .  Retrieved on , from