Eleocharis bella |
Eleocharis bicolor |
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beautiful spikerush, delicate spikerush, pretty spikerush |
two-tone spikerush |
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Habit | Plants annual, rarely perennial, usually densely tufted; rhizomes rarely evident, 0.2–0.3 mm thick, internodes 1–5 mm, scales not evident. | Plants probably perennial, tufted, not stoloniferous; rhizomes present, ± horizontal, 0.2–0.4 mm thick, firm, longer internodes 3–7 mm, scales translucent or not. |
Culms | often ascending or spreading, 4-angled or sometimes terete, sometimes sulcate, 1–7 cm × 0.2–0.3 mm, soft to firm. |
often ascending, often spotted or streaked red-brown, cross section quadrangular or broadly elliptic, often sulcate, 1.5–8(–25) cm × 0.1–0.3 mm, soft. |
Leaves | sheaths stramineous, distal sheaths often splitting abaxially, slightly inflated distally, oblique, apex acute. |
distal leaf sheaths persistent or fugaceous, closely sheathing, not conspicuously wrinkled, colorless or pale brown, sometimes spotted red-brown, delicately membranous, apex narrowly acute. |
Spikelets | ovoid, 1.5–4 × 0.8–2 mm, apex acute; floral scales 4–15, 8 per mm of rachilla, colorless or reddish brown, midrib region green, ovate-lanceolate, not folded lengthwise, 1–1.5 × 0.5–0.7 mm, mibrib obscure to somewhat keeled, apex narrowly acute to acuminate, slightly recurved. |
basal spikelets absent; never proliferous, ovoid or ellipsoid, laterally compressed or terete, 1.5–3.7 × 0.8–3 mm, apex acute; proximal scale empty, persistent, amplexicaulous, similar to floral scales; subproximal scale with a flower; floral scales distichous (spirodistichous), 8–22, 6–10 per mm of rachilla, colorless or pale brown, mottled red-brown to purple, ovate, (1–)2 × 1 mm, membranous, midribs green and red-brown, prominent, apex rounded to obtuse. |
Flowers | perianth bristles absent; anthers 0.3–0.5 mm. |
perianth bristles present or absent, (1–)4, colorless to white, vestigial to shorter than achene, 0–0.55 mm; spinules not evident at 45X; stamens (1–)3; anthers 0.35–0.45 mm; styles 2-fid (or 3-fid). |
Achenes | with angles and longitudinal ridges ca. 6–10, rather prominent, broadly ovoid, less than 2 times longer then wide, (0.55–)0.65–0.75 × 0.3–0.4 mm, apex blunt, trabeculae distinct, 20–30. |
whitish to pale brown, obovoid, biconvex, rarely trigonous, angles prominent, 0.5–0.8 × 0.4–0.6 mm, apex slightly constricted proximal to tubercle, smooth. |
Tubercles | grayish, mostly appressed, pyramidal, often depressed, 0.1–0.2 × 0.1–0.25 mm. |
sessile, green or red-brown, pyramidal, birettaform or umbonate, 0.15–0.25 × 0.3–0.4 mm. |
Eleocharis bella |
Eleocharis bicolor |
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Phenology | Fruiting spring–summer. | Fruiting summer–late fall. |
Habitat | Bare, often drying soil of stream alluvium, lake margins, wet meadows | Moist banks, freshwater, damp pine barrens |
Elevation | 200–2900 m (700–9500 ft) | 0–50 m (0–200 ft) |
Distribution |
AZ; CA; ID; MT; NM; NV; OR; WA; Mexico (Chihuahua)
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FL; GA; MS; West Indies; Central America (Nicaragua) |
Discussion | Eleocharis bella and E. acicularis seem to be amply distinct; putative hybrids are unknown. The occasional plants of E. bella with evident rhizomes, which include the type, are otherwise identical to plants apparently without rhizomes. Eleocharis bella is very similar to E. cancellata. There is an Illinois collection from Peoria in 1901, from the alluvial banks of the Illinois River. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. The culms of Eleocharis bicolor sometimes have complete transverse septa which are prominent when plants are aquatic. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 110. | FNA vol. 23, p. 96. |
Parent taxa | Cyperaceae > Eleocharis > subg. Scirpidium | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Tenuissimae |
Sibling taxa | ||
Synonyms | E. acicularis var. bella, E. acicularis var. minima | |
Name authority | (Piper) Svenson: Rhodora 31: 201. (1929) | Chapman: Fl. South. U.S., 517. (1860) |
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