Eleocharis bolanderi |
Eleocharis wolfii |
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Bolander's spikerush |
Wolf's spike-rush |
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Habit | Plants perennial, densely tufted; rhizomes caudexlike, mostly hidden by culms and roots, short, 1.5–3 mm thick, hard, cortex persistent, internodes very short, scales not evident. | Plants perennial, often forming large mats; rhizomes 0.25–0.6 mm thick, internodes 1–4 cm, scales 2 mm. |
Culms | subterete, often with to 6 prominent ridges when dry, sulcate, 10–30 cm × 0.3–0.5 mm, firm to rigid, spongy. |
sometimes decumbent, in same plant sides variably smooth or with 1 to few acute ridges (often nearly smooth or with 1 ridge on 1 side and several ridges on the other), greatly compressed, usually inrolled when dry, rectangular in cross section, 10–40 cm × 0.3–1.5 mm, 0.2–0.5 mm thick, firm, margins often sharply acute, margins and often 1 or more ridges minutely serrulate at 20–30X. |
Leaves | distal leaf sheaths persistent, not splitting, proximally brown, red, or stramineous, distally stramineous, green or reddish, papery, apex sometimes reddish, obtuse, rarely callose, tooth absent. |
distal leaf sheaths persistent, red proximally, colorless or stramineous or whitish distally, slightly inflated, thickly membranous, apex acute. |
Spikelets | ovoid, 3–8 × 2–3 mm, apex acute to obtuse; proximal scale amplexicaulous, entire; subproximal scale with flower; floral scales spreading in fruit, 8–30, 4–5 per mm of rachilla, dark brown to blackish, midrib regions often stramineous or greenish, ovate to lanceolate, 2–3 × 1.5 mm, apex entire, acute, often carinate in distal part of spikelet. |
ovoid or lanceoloid, 3–9 × 1.5–2.5 mm, apex acute; floral scales 15–30, 6 per mm of rachilla, orange-brown or often stramineous or colorless, midrib region stramineous or greenish, ovate-lanceolate, (2.2–)2.7–3.2 × 1.5 mm, midrib prominent, apex acute. |
Flowers | perianth bristles 3–6, whitish to stramineous, stout to slender, often unequal, from rudimentary to 1/2 of achene length; stamens 3; anthers dark yellow to brown, 0.9–1.4 mm; styles 3-fid. |
perianth bristles absent; anthers 1.1–1.75 mm. |
Achenes | falling with scales, stramineous, rarely dark brown, ovoid to obpyriform, slightly to greatly compressed-trigonous, rarely thickly lenticular, angles prominent or abaxial angle obscure, 0.9–1.2 × 0.65–0.8 mm, apex narrowly to broadly truncate, neck short, often compressed more than body, at 20–30X finely rugulose with more than 20 horizontal ridges in a vertical series or reticulate or cancellate. |
compressed-trigonous, with angles plus longitudinal ridges ca. 9–13, prominent, obovoid, mostly 2 times longer than wide, 0.7–0.9(–1.1) × (0.4–)0.5 mm, trabeculae 30–60, rather obscure and crowded. |
Tubercles | whitish to brown, pyramidal, lower than wide, often 3-lobed as viewed from the top, 0.1–0.3 × 0.4–0.65 mm. |
brownish, pyramidal, usually depressed, 0.1–0.15 × 0.2–0.25 mm. |
Eleocharis bolanderi |
Eleocharis wolfii |
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Phenology | Fruiting late spring–summer. | Fruiting late spring–early summer (May–Jun). |
Habitat | Fresh, often summer-dry meadows, springs, seeps, stream margins | Ephemeral pools in open grasslands, oak woodlands on river terraces, limestone barrens |
Elevation | 1000–3400 m (3300–11200 ft) | 10–500 m (0–1600 ft) |
Distribution |
CA; CO; ID; NV; OR; UT
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AL; AR; CO; IA; IL; IN; KS; LA; MN; MO; MS; ND; NY; OH; OK; TN; TX; WI
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Discussion | Eleocharis bolanderi is clearly distinct from E. montevidensis, from which it differs in its dense, tufted habit with short, caudexlike rhizomes, its leaf sheaths without a tooth, its achene and tubercle shapes, and its acute floral scales. Specimens of Eleocharis bolanderi without rhizomes or achenes are easily confused with E. decumbens, which often may be distinguished by culms 0.5–2 mm wide, and spikelets with scales sometimes more than 3 mm long. The tubercles of E. bolanderi are usually poorly developed and much lower than wide; in E. decumbens they are usually well developed and about as high as wide. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Eleocharis wolfii is presumably extirpated from Colorado, Kansas, New York (Long Island), and Ohio. It was recently rediscovered in Wisconsin. Some literature reports (e.g. from the Great Plains) are based on misidentified specimens. I have not seen specimens to verify literature reports from Alberta, Saskatchewan, Colorado, Missouri, and Nebraska. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23. | FNA vol. 23, p. 110. |
Parent taxa | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Eleocharis | Cyperaceae > Eleocharis > subg. Scirpidium |
Sibling taxa | ||
Synonyms | E. montevidensis var. bolanderi | Scirpus wolfii |
Name authority | A. Gray: Proc. Amer. Acad. Arts 7: 392. (1868) | (A. Gray) A. Gray ex Britton: in H. N. Patterson, Cat. Pl. Illinois, 46. (1876) |
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