Cyperus echinatus |
Cyperus microiria |
|
---|---|---|
globe flatsedge, teasel sedge |
lesser rice-field flatsedge |
|
Habit | Herbs, perennial, single-stemmed to loosely cespitose. | Herbs, annual, cespitose. |
Culms | basally cormlike, trigonous, (15–)30–100 cm × 0.5–3.5 mm, glabrous. |
trigonous, (5–)20–60 cm × (0.2–)0.6–2.4 mm, glabrous. |
Leaves | flat to V-shaped, 10–65 cm × 3–9 mm, adaxial surface, margins minutely scabridulous. |
(1–)3–4, V-shaped, 15–40 cm × 3–6 mm. |
Inflorescences | spikes densely globose to globose-ovoid, 8–17 mm wide; rays 3–12, 2–12 cm, scaberous adaxially especially distally; rachis 4–8 mm; bracts (3–)4–7, ascending at 30(–45)°, flat, 5–35 cm × 2–9 mm; rachilla persistent, wings 0.5–0.7 mm wide. |
spikes 2–5(–8), oblong to ovoid, 2–10 cm × 3–12 mm; rays 4–8, to 11 cm; bracts (4–)5(–7), ascending at 45°, V-shaped, (1.5–)8–30(–50) cm × 1–6 mm; rachilla persistent, wingless (successive floral scales 1.1–1.5 mm apart). |
Spikelets | 50–100, oblong-lanceoloid, ± terete-quadrangular, (3.5–)4–7 × 1–1.4 mm; distal spikelet spreading or ascending; floral scales persistent, 3–5, appressed, stramineous to brownish, 4-ribbed laterally, oblong-elliptic, 3.5–4.5 × 1–1.8 mm, membranous, apex entire or emarginate with mucro to 0.3 mm. |
10–30, spreading, compressed, linear, 4–20 × 1.5–2.1 mm; floral scales deciduous, (2–)6–26, laterally brown to golden brown, edges clear, medially green, 5-ribbed, outermost ribs more noticeable than others, obovate to nearly orbiculate, 1.3–1.8 × 1.2–1.8 mm, margins emarginate, apex mucronulate, mucro 0.2–0.25 mm. |
Flowers | anthers 0.4–0.8 mm; styles 0.5–0.6 mm; stigmas 1 mm. |
stamens 2(–3); anthers (0.2–)0.3–0.4 mm, tips of connectives reddish, less than 0.1 mm; styles less than 0.1 mm; stigmas 0.2–0.4(–0.5) mm. |
Achenes | brown, ± stipitate, oblong, (1.5–)1.8–2.3 × 0.5–0.6(–0.7) mm (1/2 length of floral scales), apex obtuse, surfaces puncticulate. |
brown, slightly stipitate, obovoid, 1.2–1.4(–1.5) × 0.5–0.7 mm, apex apiculate, surfaces puncticulate. |
Cyperus echinatus |
Cyperus microiria |
|
Phenology | Fruiting summer–early fall. | Fruiting summer. |
Habitat | Disturbed, sunny sites, in mesic places, well-drained soils | Disturbed soils |
Elevation | 0–500 m (0–1600 ft) | 0–100 m (0–300 ft) |
Distribution |
AL; AR; DC; DE; FL; GA; IL; IN; KS; KY; LA; MD; MO; MS; NC; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; WI; WV; West Indies
|
CT; KY; MA; NJ; NY; OH; PA; e Asia [Introduced in North America] |
Discussion | The records for Rhode Island and Wisconsin are according to M. L. Horvat (1941); we have not seen specimens from those states. Cyperus echinatus is usually recognized by its tight, nearly spheric spikes; it may occasionally be hard to distinguish from C. croceus and C. retrorsus. Compared to C. retrorsus, C. echinatus has larger spikelets and longer floral scales, anthers, and achenes. In contrast to C. echinatus, C. croceus has looser spikes, shorter, broader, greenish or yellowish floral scales, shorter, more ovoid achenes, and shorter anthers. Furthermore, C. echinatus is predominantly an inland species of roadsides, pastures, and other disturbed ground; C. retrorsus is primarily a coastal species and occurs in drier, sandier sites. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
The name Cyperus amuricus Maximowicz has been misapplied to C. microiria by some American authors (e.g., M. V. McGivney 1938). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 182. | FNA vol. 23, p. 166. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | Scirpus echinatus, C. ovularis, C. ovularis var. americanus, C. ovularis var. sphaericus, C. ovularis var. wolfii, C. wolfii, Kyllinga ovularis, Mariscus ovularis | C. iria var. microiria, C. iria var. parviflorus, C. iria var. rectangularis |
Name authority | (Linnaeus) Alph. Wood: Class-book Bot. ed. s.n.(b), 734. (1861) | Steudel: Syn. Pl. Glumac. 2: 23. (1855) |
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