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coastal plain flatsedge

granite flatsedge

Habit Herbs, annual, cespitose. Herbs, annual, cespitose, with roots fibrous.
Culms

1–6(–25), trigonous to roundly trigonous, (0.5–)2–5(–9) cm × 0.2–0.4–(0.6) mm, glabrous.

trigonous, glabrous.

Leaves

1–6, V-shaped, 1–6 cm × 0.3–1 mm.

V-shaped to flat, (2–)4–11 cm × 3–4 mm.

Inflorescences

heads digitate, loosely ovoid, 3–18 × 3–26 mm;

rays (0–)1–6(–8), 2.5–20(–30) mm;

bracts 2–3(–5), horizontal to ascending at 45(–60)°, V-shaped, 2–60 × 0.3–1.2 mm.

rays absent;

bracts 2–4, ± horizontal, flat, 1–6.5 cm × 2–3 mm;

rachilla persistent, wingless.

Spikelets

(3–)10–20(–30), greenish to reddish brown, narrowly ellipsoid to oblong, 3–11 × (0.8–)1.2–1.5 mm;

floral scales (3–)6–20(–28), laterally greenish to reddish brown, glossy, medially greenish to light reddish brown, strongly recurved, laterally ribless, medially strongly 3-ribbed, oblong-ovate, (0.8–)1–1.3 × 0.8–1(–1.2) mm, apex emarginate, cusp 0.6–1.2 mm.

10–40, compressed, ovoid to linear-lanceoloid, quadrangular, 5–9 × 2–3 mm;

floral scales deciduous, 5–20, spreading, pale greenish to reddish brown, laterally (5–)7–9(–13)-ribbed, ovate, 3–4 × 1–2 mm, apex straight, excurved mucronate, or cuspidate.

Flowers

stamens 2 or 3;

anthers oblong-ovoid, 0.1(–0.2) mm;

styles (0.2–)0.4–0.6 mm;

stigmas 0.3–0.5 mm.

stamens 1–2;

filaments 1.5 mm;

anthers 0.8–1 mm, connective apex reddish yellow, less than 0.1 mm;

styles 0.8–1 mm;

stigmas 1–1.2 mm.

Achenes

brown, oblong-obovoid, (0.5–)0.6 × (0.3–)0.4 mm, base cuneate, apex blunt, surfaces coarsely papillose.

brown to reddish brown, broadly ellipsoid to obovoid, 0.8–1.2 × 0.5–0.6 mm, base ± cuneate, apex truncate-obtuse, surfaces puncticulate.

Cyperus cuspidatus

Cyperus granitophilus

Phenology Fruiting summer. Fruiting summer.
Habitat Damp, disturbed soils Thin soil over outcrops of granite or sandstone of the Piedmont and inner coastal plain
Elevation 0–300 m (0–1000 ft) 50–400 m (200–1300 ft)
Distribution
from FNA
AL; FL; GA; SC; Mexico; Central America; South America
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; GA; NC; SC; TN; VA
[WildflowerSearch map]
[BONAP county map]
Discussion

Cyperus granitophilus is documented as an autotetraploid derivative of C. squarrosus (L. W. Garoni and W. H. Murdy 1964).

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

Source FNA vol. 23, p. 158. FNA vol. 23, p. 165.
Parent taxa Cyperaceae > Cyperus > subg. Pycnostachys 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. 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
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. 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
Name authority Kunth: in A. von Humboldt et al., Nov. Gen. Sp. 1: 204. (1816) McVaugh: Castanea 2: 103, figs. 4–8. (1937)
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