Cyperus drummondii |
Cyperus houghtonii |
|
---|---|---|
Drummond's sedge |
Houghton's flatsedge |
|
Habit | Herbs, perennial, cespitose; rhizomes 0.5–2 cm, often absent. | Herbs, perennial, cespitose, bases cormose, rhizomatous. |
Culms | trigonous, 35–170 cm × 2–4.7 mm, scabrid on angles. |
trigonous, 5–50 cm × 0.5–1.5 mm, 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, 12–30 cm × 1–6 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. |
spikes ± globose to broadly ovoid, 8–20 mm wide; rays 1–8 cm; rachis 2–5 mm, glabrous; bracts 3–8, weakly ascending, flat, 3–20 cm × 1–3.5 mm; rachilla deciduous, 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. |
3–18, compressed, ovoid to oblong-lanceoloid, 4–15 × 2.6–3.4 mm; floral scales deciduous, 3–18, laterally stramineous to reddish brown, laterally 3–4-ribbed, broadly ovate, 1.8–2.5 × 1.3–1.6 mm, apex with mucro 0.1–0.2 mm. |
Flowers | stamens 1–2; anthers 0.8–1.2 mm; styles 0.8–1 mm; stigmas 0.6–0.8 mm. |
anthers 0.5–0.7 mm; styles 0.4–0.6 mm; stigmas 1–1.5 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. |
dark brown, sessile, broadly ellipsoid, 1.5–2 × 1–1.5 mm, apex obtuse, apiculate, surface glabrous, puncticulate, or papillose. |
2n | = 168, 170, 172. |
|
Cyperus drummondii |
Cyperus houghtonii |
|
Phenology | Fruiting late spring–summer. | Fruiting summer. |
Habitat | Wet, relatively undisturbed habitats, especially flatwoods, ponds, seepage slopes, coastal prairies | Riverbanks, sand bars, lakeshores, sand dunes, sandy openings in woods, especially among Jack pines |
Elevation | 0–200 m (0–700 ft) | 0–1100 m (0–3600 ft) |
Distribution |
AL; FL; GA; LA; MS; SC; TX; Central America; South America; West Indies |
IL; IN; MA; MD; ME; MI; MN; NH; NJ; NY; OH; PA; VA; VT; WI; WV; MB; ON; QC
|
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.) |
|
Source | FNA vol. 23. | FNA vol. 23, p. 175. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycnostachys | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
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) | Torrey: Ann. Lyceum Nat. Hist. New York 3: 277. (1836) |
Web links |