Eleocharis bella |
Eleocharis melanocarpa |
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beautiful spikerush, delicate spikerush, pretty spikerush |
black-fruit spike-rush, black-fruit spikesedge |
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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. | |
Culms | often ascending or spreading, 4-angled or sometimes terete, sometimes sulcate, 1–7 cm × 0.2–0.3 mm, soft to firm. |
to 2 times wider than thick, 35–60(–70) cm × 0.5–1.3 mm, hard, usually with to 10 blunt ribs, at 20X often finely ridged and minutely granular. |
Leaves | sheaths stramineous, distal sheaths often splitting abaxially, slightly inflated distally, oblique, apex acute. |
distal leaf sheaths brown to reddish. |
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. |
3–12 × 3–4 mm; proximal scale amplexicaulous, 3.5–4 mm, midrib region very broad and fleshy, apex entire; subproximal scale with a flower; floral scales 30–40, 8–10 per mm of rachilla, orange-brown to stramineous, midrib region stramineous, broadly ovate, papery or sometimes membranous, 3–4 × 2 mm, apex entire, rounded. |
Flowers | perianth bristles absent; anthers 0.3–0.5 mm. |
perianth bristles present, sometimes rudimentary, brown, length variable, obscurely retrorsely spinulose; anthers brown, 1.7–2.2 mm. |
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. |
subdeltoid in outline, sometimes broadly obpyriform, equilaterally trigonous, angles prominent, 0.9–1.2 × 0.7–1.1 mm, apex truncate. |
Tubercles | grayish, mostly appressed, pyramidal, often depressed, 0.1–0.2 × 0.1–0.25 mm. |
sessile, depressed-pyramidal, often apiculate, as wide as achene, 0.3–0.5 × 0.7–1.1 mm. |
Eleocharis bella |
Eleocharis melanocarpa |
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Phenology | Fruiting spring–summer. | Fruiting summer. |
Habitat | Bare, often drying soil of stream alluvium, lake margins, wet meadows | Fresh, oligotrophic, acid, sandy or peaty, often drying shores, ponds, ditches |
Elevation | 200–2900 m (700–9500 ft) | 10–300 m (0–1000 ft) |
Distribution |
AZ; CA; ID; MT; NM; NV; OR; WA; Mexico (Chihuahua)
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AL; FL; GA; IN; MA; MI; NC; NY; RI; SC; TX; VA
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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.) |
Eleocharis melanocarpa is reported from Rhode Island; I have not seen a voucher specimen. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 110. | FNA vol. 23, p. 89. |
Parent taxa | Cyperaceae > Eleocharis > subg. Scirpidium | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Melanocarpae |
Sibling taxa | ||
Synonyms | E. acicularis var. bella, E. acicularis var. minima | |
Name authority | (Piper) Svenson: Rhodora 31: 201. (1929) | Torrey: Ann. Lyceum Nat. Hist. New York 3: 311. (1836) |
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