Eleocharis bifida S. G. Sm.

Eleocharis bifida was previously included in E. compressa. A very few specimens of E. compressa var. compressa from the states where E. bifida is known are like E. bifida except for their entire proximal floral scales and evident rhizomes.

Plants perennial, densely cespitose; rhizomes concealed by persistent culm bases, short, 4–5 mm thick, hard, cortex persistent, internodes crowded, scales decaying to coarse fibers, 1 cm, papery. Culms greatly compressed, 4–10 times wider than thick, often with 1 or 2 sharp ridges on 1 side, (8–)20–35 cm × 0.7–2.3 mm, hard, finely striate, spongy. Leaves: distal leaf sheaths persistent, not splitting, proximally red or stramineous, distally green to stramineous, inflated, papery, apex dark brown, broadly obtuse to subtruncate, callose, tooth absent. Spikelets ovoid, 4–9 × 2.5–4 mm, apex acute; proximal scale clasping 2/3–3/4 of culm, apex 2-fid; subproximal scale empty or with a flower; floral scales spreading in fruit, 30–60, 6–9 per mm of rachilla, medium or pale brown, midrib region often paler, ovate-lanceolate, 2.5–3.5 × 1.5 mm, apex 2-fid, carinate in distal part of spikelet. Flowers: perianth bristles 0(–5), stramineous to pale brown, 1/2 of to equaling achene length; stamens 3; anthers orange-brown, 0.7–1.5 mm; styles 3-fid. Achenes falling with scales, yellow-brown to medium brown, obovoid to obpyriform, nearly equilaterally trigonous, cross section circular to slightly compressed, angles obscure or evident, 0.9–1.1 × 0.6–0.75, neck usually very short, finely rugulose at 10–30X, 20 or more low, blunt horizontal ridges in vertical series. Tubercles brown, depressed-pyramidal, often rudimentary, 0.1–0.25 × 0.2–0.3 mm.

Ala., Ga., Ky., Tenn.

Fruiting spring–summer (May–Jun).

Seasonally wet places on limestone, cedar (juniper) glades, stream beds, prairies, ditches; 200–300m.

Eleocharis bifida is a species of spikesedge known by the common name glade spikerush. It is native to the Eastern United States, where it is endemic to the Interior Low Plateau and very small part of the Ridge and Valley ecoregions. This is mostly in Kentucky and Tennessee, extending into southern Indiana, northern Alabama, and northwestern Georgia. It is found only in wet areas in cedar glades, such as pools and streamsides. This narrow habitat requirement is the reason for it being considered vulnerable.

Eleocharis bifida was described to science in 2001, being separated from the similar Eleocharis compressa. Eleocharis bifida can be recognized by having wider stems and all floral scales bifid (2-lobed).

Eleocharis bifida là loài thực vật có hoa trong họ Cói. Loài này được S.G.Sm. mô tả khoa học đầu tiên năm 2001.