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Gray's flatsedge, Gray's sedge

Denton's flatsedge, hairy flatsedge

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

basally cormlike, trigonous, 5–40 cm × 0.5–1.3 mm, glabrous.

1–4, trigonous, (2–)20–50(–80) cm × (0.8–)1.5–2(–2.8) mm, basally glabrous or nearly so, apically hispidulous, on faces and angles distally, especially so immediately proximal to bracts.

Leaves

V-shaped, 5–25 cm × 1–3 mm, slightly minutely scabridulous abaxially on margins, midrib.

2–5(–7), V-shaped, (5–)15–30(–45) cm × (1.5–)2.5–5(–8) mm.

Inflorescences

spikes loosely ± globose, 6–20 mm wide;

rays 1–8 cm;

rachis 1–4 mm;

bracts 3–8, ascending, V-shaped, 3–20 cm × 1–3 mm;

rachilla deciduous, wings hyaline, 0.6 mm wide.

spike 1 (occasionally 1–2 smaller sessile spikes at base), densely cylindric, (7–)11–20(–25) × (5–) 7–10(–12) mm;

rays 3–6(–10), (1–)3–6(–18) cm, rays and rachis hispidulous;

bracts 4–8(–10), ascending at 30–60°, V-shaped, (2–)10–25(–45) cm × (1–)3–6(–8) mm;

rachilla deciduous, wings persistent, 0.3–0.4 mm wide.

Spikelets

3–18(–28), oblong-lanceoloid, compressed, 3–12 × 1.8–2.5 mm;

floral scales deciduous, 2–11, yellowish brown to reddish brown, laterally 3–4-ribbed, ovate, 2–2.8 × 1.6–2.2 mm, apex mucronulate.

(20–)70–120(–140), oblong-ellipsoid to oblong-lanceoloid, ± terete to quadrangular, (2.2–)3.4–4.5(–5.6) × (0.8–)0.9–1.2(–1.3) mm;

distal spikelet spreading or ascending;

floral scales 1(–3), appressed, stramineous, red-spotted, strongly 3(–4)-ribbed on either side of green part, medially weakly 3-ribbed, ovate to elliptic ovate, (2.4–)2.8–3.3(–3.6) × 1.6–2 mm, apex acute, mucronulate from excurrent midrib.

Flowers

anthers 0.7–1 mm;

styles 0.4–0.6 mm;

stigmas 1–2 mm.

anthers (0.3–)0.4–0.6 mm;

styles 0.4–0.6(–0.8) mm;

stigmas 1–1.4 mm.

Achenes

dark brown, ± stipitate, ellipsoid, 1.5–2 × 0.7–1 mm, apex obtuse, apiculate surfaces glabrous or puncticulate.

brown, stipitate, ellipsoid, (1.6–)1.8–2 × (0.7–) 0.8–0.9 mm, stipe 0.1–0.2 × 0.2 mm, apex ± truncate, apiculate, surfaces puncticulate to glabrous.

2n

= 166.

Cyperus grayi

Cyperus dentoniae

Phenology Fruiting summer. Fruiting mid summer–fall (Jul–Sep).
Habitat Coastal dunes, well-drained woods, railroad yards Various dry, open environments
Elevation 0–200 m (0–700 ft) 500–1000 m (1600–3300 ft)
Distribution
from FNA
CT; DE; GA; MA; MD; NC; NH; NJ; NY; PA; RI; SC; VA
[BONAP county map]
from FNA
AZ; Mexico; Central America; South America
[BONAP county map]
Discussion

Cyperus dentoniae was not treated in G. Kükenthal’s monograph (1935–1936), apparently because he did not see any materials of the species. The plant has been treated as “C. asper (Liebmann) O’Neill,” a name based on Mariscus asper Liebmann and a synonym of C. mutisii (A. B. Ayers 1946).

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

Source FNA vol. 23, p. 179. FNA vol. 23, p. 187.
Parent taxa Cyperaceae > Cyperus > subg. Cyperus 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. 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
C. acuminatus, C. aggregatus, C. alopecuroides, C. amabilis, C. articulatus, C. bipartitus, C. cephalanthus, C. compressus, C. croceus, C. cuspidatus, C. dentatus, 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. filiculmis var. grayi, C. filiculmis var. oblitus Mariscus pubescens, C. flavomariscus var. peduncularis, C. flavus var. peduncularis
Name authority Torrey: Ann. Lyceum Nat. Hist. New York 3: 268. (1836) G. C. Tucker: Syst. Bot. Monogr. 2: 56. (1983)
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