Cyperus lupulinus |
Cyperus sphaerolepis |
|||||
---|---|---|---|---|---|---|
Great Plains flatsedge, slender sand sedge |
Rusby's flatsedge, Rusby's sedge |
|||||
Habit | Herbs, perennial, cespitose, bases cormose; rhizomes knotted, beaded. | Herbs, perennial, rhizomatous. | ||||
Culms | trigonous, (3–)10–50 cm × 0.4–1.2 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 | flat, 5–40 cm × 1–3.5 mm. |
(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 rather densely ovoid to globose, 1.2–3.5 cm; rays 0 or 1–4, 1–6 cm; rachis 1–3.5 mm; bracts 2–4, horizontal to reflexed, flat, 6–25 cm; 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 | 15–60, compressed, oblong-lanceoloid, (3–)6–22 × 2.5–4 mm; floral scales deciduous, 5–22, off-white to light reddish brown, laterally 3–5-ribbed, ovate-elliptic, 2.5–4 × 2–2.6 mm, margins loosely spreading or clasping achene, apex entire to mucronate, mucro 0.05–0.2 mm. |
(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 0.3–0.6 mm; styles 1 mm; stigmas 1–1.5 mm. |
anthers 0.4–0.6 mm; styles 0.4(–0.8) mm; stigmas 0.6–1 mm. |
||||
Achenes | dark brown or black, sessile, oblong-ellipsoid to ellipsoid, 1.7–2.2 × 0.8–1.2 mm, apex obtuse, apiculate, surfaces puncticulate. |
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 lupulinus |
Cyperus sphaerolepis |
|||||
Phenology | Fruiting summer. | |||||
Habitat | Clearings in montane forests | |||||
Elevation | 1000–2500 m (3300–8200 ft) | |||||
Distribution |
AR; CO; CT; DC; DE; GA; IA; ID; IL; IN; KS; KY; MA; MD; ME; MI; MN; MO; NC; NE; NH; NJ; NY; OH; OR; PA; RI; TN; TX; VA; VT; WI; WV; NB; NS; ON; QC
|
AZ; NM; TX; Mexico |
||||
Discussion | Subspecies 2 (2 in the flora). Cyperus lupulinus was studied in detail (B. G. Marcks 1974). Ranges of the two subspecies overlap somewhat. Cyperus lupulinus subsp. lupulinus is found chiefly in the Great Plains, and subsp. macilentus is centered in the Northeast. It is seldom difficult to assign specimens to subspecies. The hybrid of Cyperus lupulinus with C. schweinitzii is C. ×mesochorus Geise. It is occasionally encountered with the two parent species in the north-central states (Illinois, Indiana, Michigan, Minnesota, and Wisconsin) and has been recorded once from Quebec. The hybrid is similar in size to C. schweinitzii; it has fewer rays, inflorescence bracts 30–45º above horizontal, and floral scales with mucros 0.4–0.5 mm. (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.) |
||||
Key |
|
|||||
Source | FNA vol. 23, p. 176. | FNA vol. 23, p. 177. | ||||
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Cyperus | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Scirpus lupulinus | C. fendlerianus var. debilis, C. fendlerianus var. leucolepis, C. leucolepis, C. rusbyi, C. schweinitzii var. debilis | ||||
Name authority | (Sprengel) Marcks: Trans. Wisconsin Acad. Sci. 62: 271. (1974) | Boeckeler: Linnaea 35: 609. (1868) | ||||
Web links |
|