Contains 33 accepted taxa overall.
Characteristics
Classification
Citation
ELEOCHARIS R. Brown, Prodr. 224. 1810.
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TYPE: Eleocharis palustris (Linnaeus) Roemer & Schultes (Scirpus palustris Linnaeus) Lectotypified by Britton, Bull. Dept. Agric. Jamaica 5(suppl. 1): 10. 1907.
Species
| Scientific Name | Common Name | Herbarium Specimens | Status | Photos |
|---|---|---|---|---|
| Eleocharis acicularis | NEEDLE SPIKERUSH | Native OBL (NWPL) OBL (DEP) | ||
| Eleocharis acutangula subsp. breviseta | ACUTE SPIKERUSH | Not Native FAC (NWPL) | ||
| Eleocharis albida | WHITE SPIKERUSH | Native OBL (NWPL) OBL (DEP) | ||
| Eleocharis atropurpurea | PURPLE SPIKERUSH | Native FACW (NWPL) OBL (DEP) | ||
| Eleocharis baldwinii | BALDWIN'S SPIKERUSH; ROADGRASS | Native OBL (NWPL) T (WAP) OBL (DEP) | ||
| Eleocharis cellulosa | GULF COAST SPIKERUSH | Native OBL (NWPL) OBL (DEP) | ||
| Eleocharis confervoides | ALGAL BULRUSH | Native OBL (NWPL) OBL (DEP) | ||
| Eleocharis elegans | ELEGANT SPIKERUSH | Not Native | ||
| Eleocharis elongata | SLIM SPIKERUSH | Native OBL (NWPL) OBL (DEP) | ||
| Eleocharis equisetoides | JOINTED SPIKERUSH | Native OBL (NWPL) OBL (DEP) | ||
| Eleocharis fallax | CREEPING SPIKERUSH | Native OBL (NWPL) OBL (DEP) | ||
| Eleocharis flavescens | YELLOW SPIKERUSH; PALE SPIKERUSH | Native OBL (NWPL) OBL (DEP) | ||
| Eleocharis geniculata | CANADA SPIKERUSH | Native FACW (NWPL) OBL (DEP) | ||
| Eleocharis interstincta | KNOTTED SPIKERUSH | Native OBL (NWPL) OBL (DEP) | ||
| Eleocharis melanocarpa | BLACKFRUIT SPIKERUSH | Native FACW (NWPL) OBL (DEP) | ||
| Eleocharis microcarpa | SMALLFRUIT SPIKERUSH | Native OBL (NWPL) OBL (DEP) | ||
| Eleocharis minima | SMALL SPIKERUSH | Native OBL (NWPL) OBL (DEP) | ||
| Eleocharis montana | MOUNTAIN SPIKERUSH | Native OBL (NWPL) OBL (DEP) | ||
| Eleocharis montevidensis | SAND SPIKERUSH | Native FACW (NWPL) OBL (DEP) | ||
| Eleocharis mutata | SCALLION GRASS | Not Native | ||
| Eleocharis nana | HAIRLIKE SPIKERUSH | Native OBL (NWPL) OBL (DEP) | ||
| Eleocharis nigrescens | BLACK SPIKERUSH | Not Native FACW (NWPL) OBL (DEP) | ||
| Eleocharis obtusa | BLUNT SPIKERUSH | Native OBL (NWPL) OBL (DEP) | ||
| Eleocharis olivacea | BRIGHTGREEN SPIKERUSH | Native OBL (NWPL) OBL (DEP) | ||
| Eleocharis parvula | DWARF SPIKERUSH | Native OBL (NWPL) OBL (DEP) | ||
| Eleocharis quadrangulata | SQUARESTEM SPIKERUSH | Native OBL (NWPL) OBL (DEP) | ||
| Eleocharis radicans | ROOTED SPIKERUSH | Native OBL (NWPL) OBL (DEP) | ||
| Eleocharis robbinsii | ROBBINS' SPIKERUSH | Native OBL (NWPL) OBL (DEP) | ||
| Eleocharis rostellata | BEAKED SPIKERUSH | Native Rare-State OBL (NWPL) OBL (DEP) | ||
| Eleocharis tortilis | TWISTED SPIKERUSH | Native FACW (NWPL) OBL (DEP) | ||
| Eleocharis tricostata | THREE-ANGLE SPIKERUSH | Native OBL (NWPL) OBL (DEP) | ||
| Eleocharis tuberculosa | CONECUP SPIKERUSH | Native OBL (NWPL) OBL (DEP) | ||
| Eleocharis vivipara | VIVIPAROUS SPIKERUSH | Native OBL (NWPL) OBL (DEP) |
Identification Key
1. Culms 0.5-9 mm wide, transverse septae conspicuous and complete or obscure and incomplete; spikelets (6)9-78 mm long, most 0.6-1.1 times as wide as the culm or 2-4 times as wide
1. Culms 0.2-1 mm wide, transverse septae incomplete and obscure; spikelets 2-12(23) mm long, 2-8 times as wide as the culm
2
2. Culms with branches in successive false whorls, which terminate in clusters of leaves essentially indistinguishable from stems, the spikelets borne singly on branches arising from among leaves; spikelets consisting of 2 scales, the single flower subtended by the distal scale (Websteria)
2. Culms unbranhced, with 1 terminal spikelets; spikelets with 4-160 scales and numerous flowers
3
3. Styles 2-fid; achene biconvex or lenticular (Maculosae group)
3. Styles 3-fid (or sometimes 2-fid in E. ambigens, E. minima, E. obtusa); achene trigonous to subterete or biconvex
1. (Key A) Spikes often subulate, generally dark brown to reddish in color, with 100-500+ densely arranged floral scales, 15-40 scales per mm; floral scales 1-3 mm long, 1-1.5 mm wide, with 1 vein (rarely 10 widely spaced veins) (Truncatae group)
2
1. Spikes mostly rounded, obutse, or abruptly acute at the tip, generally pale in color, with 4-220 floral scales, 0.5-3 scales per mm; floral scales 3-8 mm long, 2-5 mm wide, with 15+ obscure to prominent veins (subg. Limnochloa)
3
2. Culms (2.8)3-6(10) mm wide, subequal to the spikelet width; achene tubercle 2-4 times longer than wide, nearly as long as the achene body
2. Culms 0.5-3(4) mm wide, the spikelet 2-4 times wider than the culm; achene tubercle wider than or as wide as long, <1/2 as long as achene body
3. Culms 0.5-1.5 mm wide; spikelets 1.4–3 mm wide, with 4–26 floral scales; submersed culms sometimes flaccid and lacking spikelets
4
3. Culms 2.5-9 mm wide; spikelets 3–8 mm wide, with 30–220 floral scales; submersed culms not becoming flaccid and sterile
5
4. Floral scales 3.5-4.5 mm long, usually with a conspicuous brown to blackish submarginal band; achenes 0.6–1.3 mm long, 0.5–0.8 mm wide
4. Floral scales 5-8 mm long, usually without a conspicuous submarginal band; achenes 1.9–2.6 mm long, 1–1.4 mm wide
5. Culms distinctly septate (septae complete), internally hollow between septae
6
5. Culms not septate or only obscurely so (septae incomplete), internally spongy
7
6. Perianth bristles filiform, smooth to weakly toothed, shorter than to subequal to achene body; achene surface with linear-oblong cells medially and apically (rectangular towards the base)
6. Perianth bristles flattened linear-lanceolate, coarsely retrorsely spinulose, longer than achene body; achene surface with rectangular cells
7. Achene apex gradually narrowed and spongy-thickened, apex similar in texture (reticulate) to achene body except for the darkened tip (tubercle), tubercle scarcely differentiated and confluent, narrower than achene apex
8
7. Achene apex constricted, sharply differentiated from the flared base of the tubercle
9
8. Culm terete to scarcely trigonous; perianth bristles usually smooth; achene (including tubercle) 2.3-3.3 mm long
8. Culm sharply 3-angled; perianth bristles retrorsely spinulose; achene (including tubercle) 1.8-2.2 mm long
9. Culm 3-angled; perianth bristles usually retrorsely spinulose; achene 1.4-2 mm long, 1.2-1.6 mm wide, tubercle 0.3-0.8 mm long
9. Culm 4-angled; perianth bristles usually smooth to sparsely retrorsely spinulose; achene 1.8-3 mm long, 1.3-2 mm wide, tubercle 0.7-1.5 mm long
1. (Key B) Leaf sheath thin, delicate, hyaline, the margin sometimes tearing; achenes greenish to reddish or brown
2
1. Leaf sheath firm, opaque, the margin intact; achenes black
3
2. Achenes red-brown to dark brown, 0.4–0.8(1.1) mm long, 0.3–0.6 mm wide, apex usually not strongly constricted proximal to tubercle, perianth bristles usually shorter than to subequal to achene
2. Achenes green to golden-brown, 0.5–1.1 mm long, 0.4–0.8 mm wide, usually strongly constricted proximal to tubercle, perianth bristles usually longer than the achene
3. Perianth bristles colorless or white; achenes 0.3–0.5 mm long, 0.3–0.4 mm wide, apex often constricted to a neck below tubercle
3. Perianth bristles red-brown, rarely whitish; achenes 0.5–1.1 mm long, 0.3–0.7 mm wide, apex rounded below tubercle
1. (Key C) Achene surface with prominent longitudinal ribs, horizontal ridges much finer (Scirpidium group)
2
1. Achene surface smooth, honeycomb-reticulate, finely reticulate, or cancellate, the ridges all fairly equal in prominence, lacking more strongly prominent longitidinal ribs
3
2. Culms firm to flaccid, not very spongy, 1–45 cm long; anthers 0.5–1.5 mm long
2. Culms soft, very spongy, 1–12 cm long; anthers 0.3–0.5 mm
3. Achenes apex gradually narrowed to a rudimentary or scarcely distinct tubercle, similar in texture and color to the achene body or only subtly changing
4
3. Achenes apex generally narrowed below a distinct tubercle, the tubercle sharply differentiated from the achene body, the tubercle base usually flared
6
4. Culms to 100 cm long, with 8 ridges; anthers 2-2.4 mm long; achene (including indistinct tubercle) 1.5-2.5 mm long
4. Culms to 55 cm long, with or without ridges; anthers 0.7-1.5 mm long; achene (including indistinct tubercle) 0.9-1.4 mm long
5
5. Rhizomes with curved tubers; culms to 15(20) cm long, lacking ridges; perianth bristles 6
5. Rhizomes lacking curved tubers; culms to 55 cm long, with 8-12 ridges; perianth bristles absent
6. Achenes 0.7-1.7 mm long; spikelets or culm tips not proliferous (or if proliferous, achene nearly black)
7
6. Achenes 0.4-0.8(0.9) mm long, smooth, finely pitted, or cancellate; spikes or culm tips sometimes proliferous
13
7. Achene coarsely honey-comb reticulate (Tuberculosae group)
8
7. Achene smoothish to finely rugulose or cancellate
9
8. Culm usually trigonous; tubercle much narrower and shorter than the achene, much smaller than the achene
8. Culm terete; tubercle as long and as wide as achene, often larger than the achene
9. Achenes dark purplish brown to black, smooth, widest near the apex, the tubercle 0.7-1.1 mm wide, as wide as the achene; some culms often arching or decumbent and with tips rooting
9. Achenes stramineous, orangish, to brown, widest near the middle, the tubercle 0.2-0.6 mm wide and usually narrower than the achene; culms not rooting at tips
10
10. Achenes (0.9)1-1.5 mm long, (0.7)0.8-1.3 mm wide, the tubercle 0.3-0.5 mm long, 0.4-0.8 mm wide
11
10. Achenes 0.7-1 mm long, 0.6-0.8 mm wide, the tubercle 0.1-0.3 mm long, 0.2-0.4 mm wide
12
11. Spikelets 2-3 mm wide, acute at the tip, floral scales 3-5 per mm
11. Spikelets (2)3-4 mm wide, obtuse or rounded at the tip; floral scales 8-20 per mm (Ovatae group)
.
12
12. Culm base pale brownish (scarcely any red color if at all); leaf sheath apex acute to lanceolate or disintegrating; perianth bristles sometimes exceeding the tubercle
12. Culm base distinctly reddish; leaf sheath apex subtruncate to obtuse; perianth bristles not exceeding the tubercle
13. Scales distichous; spikes with 2-4 flowers
13. Scales spirally arranged (or spirodistichous); spike mostly with 4-50(75) flowers
14
14. Achenes 0.45–0.9 mm, finely reticulate or cancellate
14. Achene smooth or very finely pitted
15
15. Stolons and rhizomes absent; floral scales 1–1.2 mm long; perianth bristles absent; spikelets not proliferating
15. Stolons or rhizomes present; floral scales 1.3–2.2 mm long; perianth bristles present or absent; spikelets sometimes proliferating
16
16. Spikelet proximal scale deciduous or sometimes persistent, similar to floral scales or smaller; perianth bristles present
17
16. Spikelet proximal scale persistent, differentiated from floral scales, usually longer and resembling involucral bract, often with excurrent midrib; perianth bristles present or absent
18
17. Rhizomes absent, stolons present; spikelets often proliferating; perianth bristles colorless to stramineous, slightly shorter than to equaling tubercle; achenes sometimes spotted olive or brown
17. Rhizomes present; spikelets not proliferating; perianth bristles red-brown, equaling to exceeding tubercle; achenes not spotted
18. Proximal scale apex rounded
19
18. Proximal scale apex subacute to acute
20
19. Plants usually robust; floral scales pale brown and papery; perianth bristles well developed; achenes to 0.8 mm long, minutely pitted
19. Plants usually small; floral scales whitish with red-brown markings; perianth bristles absent or poorly developed; achenes not more than 0.6 mm long, smooth
20. Spikelet proximal scale 0.8–1 mm wide; perianth bristles 0.6–1 mm long
20. Spikelet proximal scale 0.4–0.5 mm wide; perianth bristles 0.2–0.4 mm long
Genus Synonyms
| Synonym | Full Citation | Basionym | Type |
|---|---|---|---|
| Bulbostylis | Bulbostylis Steven, Mem. Soc. Imp. Naturalistes Moscou 5: 355. 1817, nom. rej. vs. Bulbostylis Kunth 1837. | TYPE: Non designatus. | |
| Chaetocyperus | Chaetocyperus Nees von Esenbeck, Linnaea 9: 289. 1834. | TYPE: Chaetocyperus setaceus (Retzius) Nees von Esenbeck (Cyperus setaceus Retzius) Lectotypified by Pfeiffer, Nomencl. Bot. 1: 684. 1873. | |
| Clavula | Clavula Dumortier, Fl. Belg. 143. 1827. | TYPE: Non designatus. | |
| Eleogenus | Eleogenus Nees von Esenbeck, Linnaea 9: 294. 1834. | TYPE: Non designatus. | |
| Limnochloa | Limnochloa Palisot de Beauvois ex Lestiboudois f., Essai Cyper. 41. 1819. | TYPE: Non designatus. | |
| Megadenus | Megadenus Rafinesque, Neogenyton 4. 1825. | TYPE: Non designatus. | |
| Scirpidium | Scirpidium Nees von Esenbeck, Linnaea 9: 293. 1834. | TYPE: Scirpidium aciculare (Linnaeus) Nees von Esenbeck (Scirpus acicularis Linnaeus) Lectotypified by Pfeiffer, Nomencl. Bot. 2: 1097. 1874. | |
| Websteria | Websteria S. H. Wright, Bull. Torrey Bot. Club 14: 135. 1887. | TYPE: Websteria limnophila S. H. Wright 1887. |