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many-spike flatsedge

bristly flatsedge

Habit Herbs, perennial (annual?), cespitose. Herbs, perennial, cespitose, with well-developed rhizomes.
Culms

trigonous or ± terete, (3–)20–45(–70) cm × (0.8–) 1.2–2 mm, glabrous.

trigonous, 30–100 cm × 2–4 mm, basally cormlike, glabrous.

Leaves

(2–) 6–10(–16), flat to V-shaped, (2–) 10–30(–60) cm × 1–4 mm.

flat to broadly V-shaped, 20–70 cm × 4–6 mm, glabrous except for marginal prickles.

Inflorescences

spike 1, loosely ovoid to densely turbinate, 12–40 × 10–25 mm;

rachis 3–10 mm;

rays 1–8(–12), 0.5–3(–6) cm; 2d order rays absent;

if rays absent, inflorescence single dense cluster of spikelets, 12–40 mm diam.;

bracts (3–)4–6(–7), horizontal to ascending at 45°, flanged V-shaped, (2–)5–15(–23) cm × 1–4 mm.

spikes loosely to densely ovoid, oblong (2 times long as wide), 10–12 × 6–9 mm;

rays 6–11, 1–16 cm, glabrous;

bracts 5–10, ascending at 30–45°, flat, 6–25 cm × 3–6 mm;

rachilla persistent, wings 0.5 mm wide, covering nearly entire length of achene.

Spikelets

(5–)15–30(–40), spreading to appressed-ascending, linear-lanceoloid to linear, compressed, 8–18(–40) × (1–)1.3–1.6(–2) mm;

floral scales (8–)12–25(–66), laterally stramineous to light brown, medially green, laterally ribless, medially 3–5-ribbed, oblong, (1.5–)1.8–2.4 × (1–)1.2–1.4 mm, apex acute to ± acute, mucronate.

(20–)40–100(–120), proximal spikelets reflexed somewhat, distal ones divaricate, ± terete, lanceoloid, 6–6.8 × 1–1.4 mm;

floral scales persistent, 1–2(–3), appressed, golden brown, lanceolate, laterally 5–6-ribbed, 3.8–4.9 × 1.4–1.6 mm, apex mucronate, mucro at most 0.3 mm.

Flowers

stamens 2;

anthers (0.4–)0.5–0.8 mm, connective not prolonged;

styles 0.6–1(–1.4) mm;

stigmas (1–)1.4–2 mm.

anthers 1–1.3 mm;

styles 0.8–1 mm;

stigmas 2–3 mm.

Achenes

light to dark brown, oblong, (0.8–)0.9–1.1(–1.2) × 0.4–0.5(–0.6) mm, base cuneate to ± stipelike, apex truncate, apiculate, surfaces punctate to minutely punctate with raised cells.

brown, sessile, linear, 2.5–2.8 × 0.5–0.7 mm, apex obtuse, apiculate, surfaces muriculate.

Cyperus polystachyos

Cyperus hystricinus

Phenology Fruiting summer–early fall. Fruiting late summer–early fall (Jul–Sep).
Habitat Shores, ditches, swales between dunes Xeric, sandy soils of sand hills and pine barrens
Elevation 0–200 m (0–700 ft) 0–200 m (0–700 ft)
Distribution
from FNA
AL; DC; DE; FL; GA; KY; LA; MA; MD; ME; MS; NC; NJ; NY; OK; PA; SC; TX; VA; WV; Mexico; Central America; South America; Asia; Africa
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[BONAP county map]
from FNA
AL; AR; DC; DE; GA; LA; MD; MO; MS; NC; NJ; TX; VA
[WildflowerSearch map]
[BONAP county map]
Discussion

Cyperus polystachyos is polymorphic. Adequate understanding of the infraspecific variations of C. polystachyos requires a worldwide examination, which is beyond the scope of this study. The segregates, C. fugax and C. filicinus, are recognized here; they have been usually accepted by recent workers (e.g., M. L. Fernald 1950; H. A. Gleason and A. Cronquist 1991).

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

Cyperus hystricinus resembles C. plukenetii and C. retrofractus; it can be readily distinguished from both by its glabrous culms. Overly mature specimens of C. lancastriensis are frequently misidentified as C. hystricinus; C. hystricinus may be confirmed by its narrow, nearly glabrous leaves and bracts, golden brown spikelets, longer, narrower achenes, and elongated rhizome internodes (to 15 mm vs. 5 mm in 76. C. lancastriensis).

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

Source FNA vol. 23, p. 160. FNA vol. 23.
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. 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. 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. 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. 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. brizaeus, C. polystachyos var. leptostachyus, Pycreus polystachyos C. retrofractus var. hystricinus
Name authority Rottbøll: Descr. Pl. Rar., 21. (1772) Fernald: Rhodora 8: 127. (1906)
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