Eleocharis baldwinii |
Eleocharis melanocarpa |
|
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Baldwin's spike-rush |
black-fruit spike-rush, black-fruit spikesedge |
|
Habit | Plants annual(?), often mat-forming, often stoloniferous, sometimes entirely vegetative; rhizomes absent. | |
Culms | often arching, sometimes spotted or streaked red-brown, quadrangular or broadly elliptic, sulcate or not, 0.5–25(–30) cm × 0.1–0.4 mm, soft. |
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 | distal leaf sheaths persistent or disintegrating, stramineous, green, red-brown, or spotted or streaked red-brown, membranous, translucent, apex obtuse or acute. |
distal leaf sheaths brown to reddish. |
Spikelets | basal spikelets usually present, pistillate; often proliferous, ovoid, ellipsoid, or linear, clearly laterally compressed, 2.3–6.9 × 0.5–2 mm, apex acute, proximal scale empty, amplexicaulous, similar to floral scales (midribs sometimes more prominent and sometimes slightly prolonged beyond lamina); subproximal scale with a flower; floral scales clearly distichous, 3–9, 3–4 per mm of rachilla, yellowish, pale brown, or red-brown, spotted, streaked, or mottled red-brown, narrowly ovate to oblong, (1.5–)2–5 × 0.4–0.6(–1.2) mm, membranous, apex rounded, obtuse or rarely acute, midribs keeled. |
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 3–7, incurved, colorless, white, or red-brown, shorter than or equaling achene; spinules sparse, retrorse, sharply acute; stamens 3; anthers 1.4–2.2 mm; styles 3-fid. |
perianth bristles present, sometimes rudimentary, brown, length variable, obscurely retrorsely spinulose; anthers brown, 1.7–2.2 mm. |
Achenes | whitish or greenish, spotted dark green, obovoid, trigonous, angles prominent, 0.6–0.9 × 0.4–0.6 mm, apex constricted proximal to tubercle, smooth to finely cancellate at 10–20X. |
subdeltoid in outline, sometimes broadly obpyriform, equilaterally trigonous, angles prominent, 0.9–1.2 × 0.7–1.1 mm, apex truncate. |
Tubercles | pale to red-brown, pyramidal, trigonous, 0.2–0.3(–0.4) × 0.2–0.5 mm. |
sessile, depressed-pyramidal, often apiculate, as wide as achene, 0.3–0.5 × 0.7–1.1 mm. |
Eleocharis baldwinii |
Eleocharis melanocarpa |
|
Phenology | Fruiting early spring–winter. | Fruiting summer. |
Habitat | Freshwater to moist terrestrial sites, pine savannas, cypress ponds, lakeshores | Fresh, oligotrophic, acid, sandy or peaty, often drying shores, ponds, ditches |
Elevation | 0–60 m (0–200 ft) | 10–300 m (0–1000 ft) |
Distribution |
AL; AR; FL; GA; LA; MS; NC; SC; TX
|
AL; FL; GA; IN; MA; MI; NC; NY; RI; SC; TX; VA
|
Discussion | Coarse plants of Eleocharis baldwinii usually bear more achenes per spikelet, dark colored achenes, culms gray-green when dried, and yellowish sheaths. Finer plants often bear few achenes per spikelet, whitish achenes, culms that are mid green when dried, and reddish sheaths. Achene color may relate to maturity, with darker achenes being fully mature. Although these variants appear to intergrade, they may be recognizable taxonomically. The longer floral scales in the spikelet are usually 3.5– 5 mm. We have not seen vouchers to verify the report of Eleocharis baldwinii from Virginia. (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. 98. | FNA vol. 23, p. 89. |
Parent taxa | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Tenuissimae | Cyperaceae > Eleocharis > subg. Eleocharis > sect. Eleocharis > ser. Melanocarpae |
Sibling taxa | ||
Synonyms | Chaetocyperus baldwinii | |
Name authority | (Torrey) Chapman: Fl. South. U.S., 519. (1860) | Torrey: Ann. Lyceum Nat. Hist. New York 3: 311. (1836) |
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