Eleocharis bella |
Eleocharis brachycarpa |
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beautiful spikerush, delicate spikerush, pretty spikerush |
shortfruit 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 annual, densely cespitose; rhizomes obscured among culm bases, 0.2 mm thick, internodes to 4 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. |
mostly ascending, 4-angled, sulcate, 5 cm × 0.1–0.2 mm, soft. |
Leaves | sheaths stramineous, distal sheaths often splitting abaxially, slightly inflated distally, oblique, apex acute. |
distal leaf sheaths persistent, colorless, translucent, 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. |
ovoid, 2–3 × 1–2 mm, apex blunt; floral scales 10–30, ca. 10 per mm of rachilla, orange-brown to stramineous with broad colorless margin, midrib region stramineous, lanceolate, folded lengthwise, 1.5–2 × 0.8–1 mm, midrib prominent, apex acuminate. |
Flowers | perianth bristles absent; anthers 0.3–0.5 mm. |
perianth bristles absent; anthers 0.7–1.2 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. |
whitish, broadly obpyriform, much less than 2 times longer than wide, angles and longitudinal ridges ca. 6, obscure, 0.4 × 0.3 mm, apex blunt, trabeculae 20, indistinct, crowded. |
Tubercles | grayish, mostly appressed, pyramidal, often depressed, 0.1–0.2 × 0.1–0.25 mm. |
brownish, not appressed, mostly pyramidal, 0.1 × 0.1 mm. |
Eleocharis bella |
Eleocharis brachycarpa |
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Phenology | Fruiting spring–summer. | Fruiting winter–spring. |
Habitat | Bare, often drying soil of stream alluvium, lake margins, wet meadows | Wet soils |
Elevation | 200–2900 m (700–9500 ft) | 0–20 m (0–100 ft) |
Distribution |
AZ; CA; ID; MT; NM; NV; OR; WA; Mexico (Chihuahua)
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TX; Mexico (Tamaulipas) |
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. Eleocharis brachycarpa is unique among the North American members of subg. Scirpidium in its floral scales, which are markedly spreading in fruit, often apparently decussate when pressed, narrowly lanceolate, and folded lengthwise so that they do not press open and flat. It is apparently very rare and local. It is admitted to the flora only on the basis of labels on a paratype (Berlandier 996) and on Berlandier 2426, both of which read “In locis paludosis – De Matamoros a las Nueces [River, Texas], Ap. 1834.” H. K. Svenson (1929) mistranscribed the locality “Nueces,” publishing it as “Mueres.” We have also seen a specimen from Mexico, Tamaulipas, 24 mi. N of San Fernando, edges of resacas, elev. 15 m, 1959, M.C. Johnston 4882C (TEX). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 110. | FNA vol. 23, p. 111. |
Parent taxa | Cyperaceae > Eleocharis > subg. Scirpidium | Cyperaceae > Eleocharis > subg. Scirpidium |
Sibling taxa | ||
Synonyms | E. acicularis var. bella, E. acicularis var. minima | |
Name authority | (Piper) Svenson: Rhodora 31: 201. (1929) | Svenson: Rhodora 31: 200, plate 190, fig. 34. (1929) |
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