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Piedmont flatsedge

Latin American flatsedge

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

single or close together, trigonous, (10–)40–80(–120) cm × 1.2–2.5(–5) mm, glabrous.

trigonous, (1–) 20–40(–75) cm × 1–1.5(–2.5) mm, glabrous.

Leaves

2–5, pleated, (10–)20–50(–90) cm × 2–5(–10) mm.

inversely W-shaped, 10–40(–70) cm × (1–)3–6(–10) mm.

Inflorescences

spikes 1–4(–7), loose, broadly ovoid to ovoid-pyramidal, 25–35 × 25–35 mm;

rays (4–)5–6(–8), (1–)3–8(–16) cm, glabrous; 2d order rays (0–)1–5, 5–15(–50) mm;

bracts 4–7, ascending at 30–45°, pleated, (5–)20–40(–60) × (2–)3–8(–11) mm; 2d order bracts 1–4 per ray, 5–10(–30) × 0.5–1 mm, scabridulous;

rachilla persistent, wingless (or very narrowly winged, not clasping achene).

spikes 1(–3), broadly and loosely ovoid to oblong-ellipsoid, (15–)20–30(–50) × 20–30(–45) mm;

bracts (3–)5–7(–10), ascending at 30(–45)°, inversely W-shaped, 10–30(–50) cm × (1–)3–5(–11) mm;

rays (2–)3–6(–12), (1–)3–10(–17) cm;

rachilla deciduous, wings ca. 0.3 mm wide.

Spikelets

(10–)20–35(–45), seemingly flattened proximally from spreading floral scales, becoming terete apically, linear, (10–)13–18(–25) × 1.2–1.5(–1.6) mm;

floral scales deciduous, (10–)12–20(–25), laterally light reddish brown to dark red, medially greenish, laterally ribless, medially 3–5-ribbed, oblong-ovate, 1.7–2(–2.4) × 0.9–1.2 mm, apex obtuse, barely reaching next scale, apex entire, emarginate, mucro at most 0.3 mm.

(10–)25–50(–100), ± terete, (appearing compressed due to excurved apices of floral scales), (8–)12–15(–24) × (0.8–)1.1–1.4(–1.8) mm;

floral scales persistent, (4–)6–8(–14), golden brown, off-white to stramineous, densely red-glandular punctate, green medially, 3–4-ribbed laterally, 3–5-ribbed medially, oblong-lanceolate, (3.2–)4–4.5 × 1.2–1.6 mm, apex blunt, mucronulate to mucronate, mucro 0.2–0.5 mm;

proximal scales mucronulate, distal scales mucronate;

terminal scale conduplicate.

Flowers

anthers 0.4–0.5 mm;

styles 0.3–0.6 mm;

stigmas 1–1.8(–2) mm.

anthers 0.5–0.8(–1.4) mm;

styles 0.8–1 mm;

stigmas 1–2 mm.

Achenes

dark brown, narrowly oblong, (1.3–)1.4–1.6(–1.7) × (0.3–)0.4–0.5 mm, base cuneate to ± stipelike, apex acute, not apiculate, surfaces papillose.

brown, ± sessile to stipitate, oblong-ellipsoid, 1.7–2 × 0.6–0.7 mm, 0.1(–0.2) × 0.2 mm, apex rounded, apiculate from dark purple style base, surfaces papillose.

Cyperus distans

Cyperus lentiginosus

Phenology Fruiting summer. Fruiting spring–summer.
Habitat Marshes Thickets, open woods
Elevation 0 m (0 ft) 0–50 m (0–200 ft)
Distribution
from FNA
FL; NC; Mexico; South America; West Indies (Dominican Republic south through the Lesser Antilles); Asia; Africa
[BONAP county map]
from FNA
FL; TX; Mexico; West Indies
[BONAP county map]
Discussion

Cyperus lentiginosus has been treated as a variety of C. tenuis (G. Kükenthal 1935–1936). The two taxa differ in the longer scales with cuspidate apices of C. lentiginosus, the inversely W-shaped leaves and bracts (those of C. tenuis are V-shaped), and the open spikes (those of C. tenuis are dense).

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

Source FNA vol. 23. FNA vol. 23.
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. 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
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. 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. elatus C. strigosus var. gracilis, C. tenuis var. lentiginosus
Name authority Linnaeus f.: Suppl. Pl., 103. (1782) Millspaugh & Chase: Publ. Field Columbian Mus., Bot. Ser. 3: 74. (1903)
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