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black flatsedge, brown cyperus

Baldwin's flatsedge

Habit Herbs, perennial, rhizomatous. Herbs perennial, cespitose.
Culms

solitary or close together, trigonous, 5–40(–95) cm, glabrous.

trigonous, (4–)14–45 cm × 1–2 mm, glabrous.

Leaves

(2–)3–7, broadly V-shaped, 3–20(–30) cm × 1.5–3 mm.

yellow-green, flat, 18–44 cm × 3–4.5 mm.

Inflorescences

spikes loosely to densely ovoid to hemispheric, 7–16 mm diam.;

rachis 1–2 mm, or absent;

rays 1–2, 3–45 mm;

if rays absent, inflorescence sessile, dense, 6–20 mm diam;

bracts 2–3, horizontal to reflexed downward, broadly V-shaped, 1–15 cm × 1–3 mm.

spikes densely to loosely globose to ovoid, 10–20 mm wide;

rays (3–)5–9(–14), 1–15(–26) cm;

rachis 3–6(–9) mm;

bracts (4–)6–9(–11), horizontal to ascending at 45°, flat, 1–30 cm × 0.5–4 mm;

rachilla deciduous, wings persistent, 0.3–0.5(–0.8) mm wide.

Spikelets

(3–)5–25(–60), linear to oblong-linear, (3–)5–9 × 1.8–2.3 mm;

floral scales 4–18, closely imbricate, chestnut brown, black, or brown, medially green or greenish brown, laterally ribless, medially 2(–3)-ribbed, distinctly 2-keeled basally, ovate to orbiculate, 1.5–2.1 × 1.4–2.2 mm, apex obtuse.

(10–)30–50, oblong to lanceoloid, quadrangular to subterete, compressed, 4–8 × 1–1.3 mm;

distal spikelet spreading or ascending;

floral scales persistent, (1–)2–4(–6), appressed, whitish with red speckles, laterally 2–4-ribbed, ovate, 2.3–3.6 × 1.8–2.2 mm.

Flowers

stamens 2;

anthers 0.6–0.8 mm, connectives not prolonged;

styles 0.4–0.6 mm;

stigmas 0.7–2.1 mm.

anthers 0.5 mm;

styles 0.6–1.3 mm;

stigmas 1.2–2.6 mm.

Achenes

brown, ellipsoid, 1.2–1.4 × 0.6–0.8 mm, network of ridges forming isodiametric or square cells, slightly stipitate, apex apiculate, surfaces minutely punctate.

reddish brown to nearly black, sessile, oblong, ellipsoid, 2–2.4 × 0.4–0.5(–0.7) mm, apex ± truncate-emarginate, apiculate, surfaces puncticulate.

Cyperus niger

Cyperus croceus

Phenology Fruiting summer. Fruiting summer–early fall.
Habitat Swamps, ditches, wet pastures, seeps in montane forests Disturbed, sunny areas, coastal rocks, moist thickets
Elevation 0–1200 m (0–3900 ft) 0–200 m (0–700 ft)
Distribution
from FNA
AZ; CA; NM; OK; TX; Mexico; Central America; South America
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; DE; FL; GA; LA; MD; MO; MS; NC; NJ; OK; PA; SC; TN; TX; VA; WV; Mexico; Central America; West Indies; South America (Venezuela)
[WildflowerSearch map]
[BONAP county map]
Discussion

Six varieties (Cyperus niger var. niger, var. castaneus, var. robustus, var. lorentizianus, var. intricate-ramosus, and var. pseudo-elegantulus) were recognized by G. Kükenthal (1935–1936). Based on field observations and measurements of hundreds of collections from Mexico, where the species is most plentiful, it does not seem possible to recognize any of the infraspecific taxa (G. C. Tucker 1983, 1994; G. C. Tucker and R. McVaugh 1993).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Cyperus globulosus Aublet is a synonym of C. luzulae (Linnaeus) Rottbøll ex Retzius, which is a widespread neotropical species, and it has long been misapplied to Cyperus croceus (G. C. Tucker 1987).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 23. FNA vol. 23, p. 183.
Parent taxa Cyperaceae > Cyperus > subg. Pycreus Cyperaceae > Cyperus > subg. Cyperus
Sibling taxa
C. acuminatus, C. aggregatus, C. alopecuroides, C. amabilis, C. articulatus, C. bipartitus, C. cephalanthus, C. compressus, C. croceus, C. cuspidatus, C. dentatus, C. dentoniae, C. diandrus, C. difformis, C. digitatus, C. dipsaceus, C. distans, C. distinctus, C. drummondii, C. echinatus, C. elegans, C. entrerianus, C. eragrostis, C. erythrorhizos, C. esculentus, C. fendlerianus, C. filicinus, C. filiculmis, C. filiformis, C. flavescens, C. flavicomus, C. floribundus, C. fugax, C. fuligineus, C. fuscus, C. giganteus, C. gracilis, C. granitophilus, C. grayi, C. grayoides, C. haspan, C. hermaphroditus, C. houghtonii, C. hypopitys, C. hystricinus, C. involucratus, C. iria, C. laevigatus, C. lancastriensis, C. lanceolatus, C. lecontei, C. lentiginosus, C. ligularis, C. lupulinus, C. manimae, C. microiria, C. mutisii, C. ochraceus, C. odoratus, C. onerosus, C. ovatus, C. owanii, C. oxylepis, C. pallidicolor, C. papyrus, C. parishii, C. pilosus, C. planifolius, C. plukenetii, C. polystachyos, C. prolifer, C. prolixus, C. pseudothyrsiflorus, C. pseudovegetus, C. pumilus, C. reflexus, C. refractus, C. retroflexus, C. retrofractus, C. retrorsus, C. rotundus, C. sanguinolentus, C. schweinitzii, C. serotinus, C. seslerioides, C. setigerus, C. spectabilis, C. sphacelatus, C. sphaerolepis, C. squarrosus, C. strigosus, C. surinamensis, C. tetragonus, C. thyrsiflorus, C. virens
C. acuminatus, C. aggregatus, C. alopecuroides, C. amabilis, C. articulatus, C. bipartitus, C. cephalanthus, C. compressus, C. cuspidatus, C. dentatus, C. dentoniae, C. diandrus, C. difformis, C. digitatus, C. dipsaceus, C. distans, C. distinctus, C. drummondii, C. echinatus, C. elegans, C. entrerianus, C. eragrostis, C. erythrorhizos, C. esculentus, C. fendlerianus, C. filicinus, C. filiculmis, C. filiformis, C. flavescens, C. flavicomus, C. floribundus, C. fugax, C. fuligineus, C. fuscus, C. giganteus, C. gracilis, C. granitophilus, C. grayi, C. grayoides, C. haspan, C. hermaphroditus, C. houghtonii, C. hypopitys, C. hystricinus, C. involucratus, C. iria, C. laevigatus, C. lancastriensis, C. lanceolatus, C. lecontei, C. lentiginosus, C. ligularis, C. lupulinus, C. manimae, C. microiria, C. mutisii, C. niger, C. ochraceus, C. odoratus, C. onerosus, C. ovatus, C. owanii, C. oxylepis, C. pallidicolor, C. papyrus, C. parishii, C. pilosus, C. planifolius, C. plukenetii, C. polystachyos, C. prolifer, C. prolixus, C. pseudothyrsiflorus, C. pseudovegetus, C. pumilus, C. reflexus, C. refractus, C. retroflexus, C. retrofractus, C. retrorsus, C. rotundus, C. sanguinolentus, C. schweinitzii, C. serotinus, C. seslerioides, C. setigerus, C. spectabilis, C. sphacelatus, C. sphaerolepis, C. squarrosus, C. strigosus, C. surinamensis, C. tetragonus, C. thyrsiflorus, C. virens
Synonyms C. diandrus var. castaneus, C. melanostachyus, C. niger var. castaneus C. baldwinii, C. cyclostachyus, C. echinatus var. multiflora, C. globulosus var. pseudofiliculmis, C. globulosus var. robustus, C. plankii, C. retrorsus var. robustus, Mariscus bracheilema, Mariscus brittonii
Name authority Ruiz & Pavón: Fl. Peruv. 1: 47. (1798) Vahl: Enum. Pl. 2: 357. (1805)
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