Cyperus grayoides |
Cyperus sphaerolepis |
|
---|---|---|
Illinois flatsedge, Mohlenbrock's sedge, umbrella sedge |
Rusby's flatsedge, Rusby's sedge |
|
Habit | Herbs, perennial, cespitose, rhizomatous, tuberlike. | Herbs, perennial, rhizomatous. |
Culms | trigonous, 5–35 cm × 0.7–1.2 mm, glabrous. |
basally cormlike, trigonous, (8–)15–40(–60) cm × (0.4–)0.8–1.5(–2) mm, glabrous or sparsely to densely scabridulous to minutely scabrid on angles or usually on surface, just proximal to bracts or over distal few centimeters. |
Leaves | V-shaped, 5–25 cm × 1.5–3.5 mm, slightly scabridulous on abaxial margins, midrib. |
(1–)3–4, V-shaped, (7–)15–25(–40) cm × 1–3(–5) mm, sparsely minutely scabridulous on margins and keel in distal 1/3, otherwise glabrous. |
Inflorescences | spikes loosely ± globose, 15–25 mm wide; rays 1–10 cm; rachis 1–4 mm; bracts 3–7, ascending, V-shaped, 3–20 cm × 1–3 mm; rachilla deciduous, wingless. |
spikes 1–3, sessile (occasionally 1 spike on peduncle 5–20 cm, produced from axil of distalmost leaf), loosely cylindric to oblong-ovoid, (9–)15–30(–45) × (3–)8–15(–18) mm; bracts 2–3(–7), longest erect, or very nearly so, others spreading, (1–)3–20(–26) cm × (0.5–)1–3(–5) mm; rays (1–)2–6(–11), (1–)2–7(–12) cm, in some depauperate plants rays less than 1 cm; rachilla ± deciduous, wingless. |
Spikelets | 3–24, compressed, oblong-lanceoloid, 4–12 × 2.5–3.2 mm; floral scales deciduous, 3–9, pale reddish brown, ovate, laterally 3–5-ribbed, 2.5–3 × 2–2.4 mm, apex acute to obtuse. |
(4–)8–25(–35), oblong-ellipsoid to linear, compressed-quadrangular, (2–)7–11(–15) × (2–)2.4–3.2(–3.5) mm; floral scales (1–)4–8(–14), laterally dull whitish, stramineous, or light brown, or reddish brown to deep red, often red-dotted especially near keel, medially greenish, broadly ovate-deltate to ± orbiculate, laterally strongly 3(–4)-ribbed, medially weakly 1–3-ribbed, (1.6–)1.8–2.4 × (1.8–)2.2–2.8 mm, margins clear, erose especially apically, apex obtuse, tipped with straight mucro 0.1–0.2(–0.3) mm. |
Flowers | anthers 1–1.2 mm; styles 0.4–0.6 mm; stigmas 1–2 mm. |
anthers 0.4–0.6 mm; styles 0.4(–0.8) mm; stigmas 0.6–1 mm. |
Achenes | dark brown, ± stipitate, ellipsoid, 2–2.4 × 0.9–1.2 mm, apex obtuse, apiculate, surfaces glabrous, puncticulate, or papillose. |
finely reticulate with isodiametric cells, this layer gradually wearing away to reveal inner brown to reddish brown layer, stipitate, ovoid to obovoid, 1.4–1.6(–1.9) × 1–1.3(–1.4) mm, base cuneate to ± attenuate, stipe 0.1–0.2 × 0.2 mm, apex obtuse, slightly apiculate, inner layer papillose. |
2n | = 166. |
|
Cyperus grayoides |
Cyperus sphaerolepis |
|
Phenology | Fruiting summer. | Fruiting summer. |
Habitat | Sand prairies, waste places, fallow fields | Clearings in montane forests |
Elevation | 100–300 m (300–1000 ft) | 1000–2500 m (3300–8200 ft) |
Distribution |
AR; IL; LA; MO; TX
|
AZ; NM; TX; Mexico |
Discussion | Of conservation concern. Cyperus grayoides is in the Center for Plant Conservation’s National Collection of Endangered Plant’s. See frontispiece. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Cyperus sphaerolepis has long been known by the synonym C. rusbyi and has been treated as a variety of C. fendlerianus. Specific status for C. sphaerolepis is supported by B. G. Marcks (1972) and G. C. Tucker (1994). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23. | FNA vol. 23, p. 177. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | C. fendlerianus var. debilis, C. fendlerianus var. leucolepis, C. leucolepis, C. rusbyi, C. schweinitzii var. debilis | |
Name authority | Mohlenbrock: Brittonia 11: 255, fig. 1. (1959) | Boeckeler: Linnaea 35: 609. (1868) |
Web links |