Eleocharis bolanderi |
Eleocharis ravenelii |
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Bolander's spikerush |
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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, densely tufted; rhizomes mostly hidden by aerial shoots and roots, not long, 2–3 mm thick, hard, cortex persistent?, internodes very short, scales persistent, 4–7 mm, membranous, slightly fibrous. |
Culms | subterete, often with to 6 prominent ridges when dry, sulcate, 10–30 cm × 0.3–0.5 mm, firm to rigid, spongy. |
terete, when dry with to 12 blunt ribs, 20–55 cm × 0.5–1.1 mm, soft to firm, internally mostly hollow with complete transverse septa 2–4 mm apart, evident only on sectioning culm. |
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, not splitting, proximally dark red, distally stramineous or reddish, thinly papery, apex often red to brown, obtuse to subtruncate, slightly callose, tooth present, 0.5–1(–3.7) mm. |
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. |
lanceoloid, 5–13 × 2–2.5 mm, apex acute to obtuse; proximal scale amplexicaulous, entire; subproximal scale empty; floral scales appressed in fruit, 10–100, 10–12 per mm of rachilla, medium brown to stramineous, midrib regions often greenish, ovate, 1–1.5 × 1 mm, entire, apex rounded to subacute, carinate in distal part of spikelet. |
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 5–6, pale brown, stout, equaling achene; stamens 3; anthers brown, 0.4–0.9 mm; styles 3-fid or a few 2-fid in the same spikelet. |
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. |
falling with scales, green or medium or dark brown, obpyriform, compressed-trigonous or some biconvex in same spikelet, angles prominent, 0.6–0.8 × 0.5–0.6 mm, neck short or absent, smooth or very finely reticulate at 20–30X. |
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. |
brown, depressed-pyramidal, 0.1–0.2 × 0.2–0.3 mm. |
Eleocharis bolanderi |
Eleocharis ravenelii |
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Phenology | Fruiting late spring–summer. | Fruiting spring–fall. |
Habitat | Fresh, often summer-dry meadows, springs, seeps, stream margins | Fresh, wet to damp, seasonally wet depressions, flatwoods, ditches |
Elevation | 1000–3400 m (3300–11200 ft) | 0–200 m (0–700 ft) |
Distribution |
CA; CO; ID; NV; OR; UT
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TX; Mexico (San Luis Potosí) |
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.) |
Of conservation concern. Eleocharis ravenelii is apparently very uncommon in North America. It is often mistaken for very slender-stemmed E. montana, which differs in its spikelets with floral scales 1.5 mm or more, 100–500 per spikelet and 15–40 per mm of rachilla, its mostly larger and biconvex achenes, and its culm septa usually evident without sectioning the culm. Although the holotype of E. ravenelii (NY), from Corpus Christi, Texas, lacks culm bases and leaf sheaths, its culms, spikelets, floral scales, and achenes are typical of the later E. austrotexana M. C. Johnston. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23. | FNA vol. 23. |
Parent taxa | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Eleocharis | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Eleocharis |
Sibling taxa | ||
Synonyms | E. montevidensis var. bolanderi | E. austrotexana |
Name authority | A. Gray: Proc. Amer. Acad. Arts 7: 392. (1868) | Britton: in J. K. Small, Fl. S.E. U.S., 184, 1327. (1903) |
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