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Drummond's sedge

granite flatsedge

Habit Herbs, perennial, cespitose; rhizomes 0.5–2 cm, often absent. Herbs, annual, cespitose, with roots fibrous.
Culms

trigonous, 35–170 cm × 2–4.7 mm, scabrid on angles.

trigonous, glabrous.

Leaves

4–12, with readily visible cross ribs especially on abaxial surface, flat to V-shaped, 25–100 cm × 2.4–11 mm.

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

Inflorescences

heads digitate, globose, 1–1.7 cm diam.;

rays 3–5, 1–7 cm; 2d order rays absent;

bracts 3–5, horizontal to ascending at 30°, with prominent cross ribs, V-shaped, (4–)11–35(–48) cm × 1–6.7 mm (longest 1/2 as long as culm); 2d order bracts absent.

rays absent;

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

rachilla persistent, wingless.

Spikelets

10–40, oblong to linear-lanceoloid, 5–1.8 × 1.5–2.2 mm;

floral scales 18–42, pale grayish green, turning brownish, proximally greenish or brownish, 2-keeled, weakly to distinctly 1-ribbed, proximal 1/2 2-ribbed, ovate, 1.4–1.6 × 0.9–1.4 mm, acute (sometimes mucronulate), apically glabrous, occasionally scabridulous.

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 1–2;

anthers 0.8–1.2 mm;

styles 0.8–1 mm;

stigmas 0.6–0.8 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, slightly stipitate, oblong-ellipsoid (2.4–3.9 times longer than wide), 1–1.2 × 0.3–0.5 mm, apical beak 0.1–0.5 mm, surfaces glabrous.

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 drummondii

Cyperus granitophilus

Phenology Fruiting late spring–summer. Fruiting summer.
Habitat Wet, relatively undisturbed habitats, especially flatwoods, ponds, seepage slopes, coastal prairies Thin soil over outcrops of granite or sandstone of the Piedmont and inner coastal plain
Elevation 0–200 m (0–700 ft) 50–400 m (200–1300 ft)
Distribution
from FNA
AL; FL; GA; LA; MS; SC; TX; Central America; South America; West Indies
[BONAP county map]
from FNA
AL; GA; NC; SC; TN; VA
[WildflowerSearch map]
[BONAP county map]
Discussion

Cyperus drummondii has been treated as a synonym (G. C. Tucker 1994), or a variety (G. Kükenthal 1935–1936), or a subspecies of C. virens (M. F. Denton 1978b). Recent quantitative and field studies (J. R. Carter et al. 1999) provided compelling evidence that specific status is appropriate.

Compared to Cyperus virens, C. drummondii is a taller species of less disturbed habitats and has narrower spikelets, ovate scales, and fewer inflorescence bracts. Cyperus virens and C. drummondii are readily distinguished from other Cyperus species in the United States by their sharply angled, scabrid culms and conspicuously septate leaf blades.

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

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. 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. cuspidatus, C. dentatus, C. dentoniae, C. diandrus, C. difformis, C. digitatus, C. dipsaceus, C. distans, C. distinctus, 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
Synonyms C. robustus, C. virens subsp. drummondii, C. virens var. drummondii, C. virens var. robustus
Name authority Torrey & Hooker: Ann. Lyceum Nat. Hist. New York 3: 437, errata. (1836) McVaugh: Castanea 2: 103, figs. 4–8. (1937)
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