| Author | (Nees) Kunth | |
| Distribution | Known only from 2 specimens at NY Botanical Garden, collected "prope Wilmington" in 1867 by William Canby. Annotated by sedge expert J. Bruhl in 1995. The native or alien status in NC is not certain at this time.
Southeastern NC to FL, W.I., Mex, S.A. (where considered native), Africa. | |
| Abundance | Very rare, if still present in state. | |
| Habitat | No habitat given on specimen sheets. Presumably in a disturbed moist or wet area. | |
| Phenology | Mature fruits collected on 1 October. | |
| Identification | Eleocharis nigrescens is very similar to E. microcarpa and E. brittonii; all have filiform culms and small spikelets. E. nigrescens and some brittonii lack bristles at the base of the achene, these present in microcarpa and in other brittonii. The bases of leaf sheaths are pinkish to straw color in brittonii but purple-red in nigrescens. | |
| Taxonomic Comments | A synonym is E. carolina Small.
The genus Eleocharis, the spikerushes, are unusual members of the sedge family in that the culms (flowering stems) are round or oval (rarely triangular) in cross-section, rather than triangular in the great majority of our sedges. In addition, leaf blades are absent; just 1-2 basal sheaths are present at the base of the culm. There is a single, cylindrical or narrowly ovoid, spikelet of florets at the culm summit. Details of achene (seed) shape, color, ornamentation, bristle length, and beak (tubercle) shape and size, are critical ID factors. | |
| Other Common Name(s) | | |
| State Rank | SE? | |
| Global Rank | GNR | |
| State Status | | |
| US Status | | |
| USACE-agcp | | |
| USACE-emp | | |
