Fimbristylis puberula |
Fimbristylis dichotoma |
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hairy fimbry |
fork fimbry |
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Habit | Plants perennial, mostly loosely cespitose, to 100 cm, bases swollen; rhizomes short, knotty, or scaly, slender, contorted. | Plants perennial, cespitose, (10–) 20–80 cm, base thickened, not bulbous; rhizomes absent. | ||||
Culms | sometimes solitary, narrowly linear, distally angular, glabrous. |
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Leaves | ascending, from 1/3 as long to equally as long as culms, glabrous to pubescent; sheaths apically ciliate; ligule essentially absent or (in rhizomatous individuals) present, complete or incomplete; blades narrowly linear, 1–2 mm wide, mostly strongly involute, scabrid-ciliate. |
nearly distichous, spreading to ascending, 1/2 length of culms; sheaths distally ciliate, backs mostly glabrous; ligule line of short hairs; blades narrowly linear, 2–3 mm wide, flat to broadly involute, scabridciliate, adaxially smooth or hirtellous. |
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Inflorescences | anthelae simple or compound, compact or diffuse, mostly broad, ascending-branching; scapes slender, wandlike, 1 mm thick; lower leafy involucral bracts exceeded by or exceeding panicle. |
anthelae compound, dense or open, ascending-branched, longer than broad; scapes slender, 1 mm wide, slightly compressed distally; proximalmost involucral bract exceeding anthela. |
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Spikelets | variously red-brown, broadly ovoid to lance-cylindric, 5–10 mm; fertile scales broadly ovate, obtuse or obtuse-angled, 2.5–3.5 mm, abaxially glabrous or variously puberulent, midrib excurrent as mucro. |
pale drab brown to chestnut brown, ovoid-lanceoloid, 4–8 mm; fertile scales broadly oblong or ovate, 2 mm, acute to obtuse angled, glabrous, midrib reaching scale tip or excurrent, finely mucronate. |
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Flowers | stamens 3; styles 2-fid, flat, fimbriate. |
stamens 1–2; styles 2-fid, flat, fimbriate. |
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Achenes | yellowish to dark brown, lenticular-obovoid, 1 mm, with 11–20 vertical lines of horizontally rectangular or isodiametric, distinct or indistinct pits. |
white to brownish, lenticular, obovoid, 1–1.2 mm, cancellate, each face longitudinally with (5–)10–12 ribs, connected by vertical rows of horizontally rectangular pits. |
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2n | = 20. |
= 20, 30. |
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Fimbristylis puberula |
Fimbristylis dichotoma |
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Phenology | Fruiting summer–fall, into winter southward. | |||||
Habitat | Moist, usually sandy waste areas, roadsides, low fields, and savannas | |||||
Elevation | 0–200 m (to 2000 m, tropics) (0–700 ft (to 6600 ft, tropics)) | |||||
Distribution |
AL; AR; AZ; DE; FL; GA; IL; IN; KS; KY; LA; MD; MI; MO; MS; NC; NE; NJ; NM; NY; OH; OK; SC; TN; TX; UT; VA; ON
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AL; FL; GA; LA; MS; NC; SC; TX; Mexico; Central America; South America; Atlantic Islands; Pacific Islands; Indian Ocean Islands; West Indies; Africa; Eurasia; Bermuda; Australia [Introduced in North America]
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Discussion | Varieties 2 (2 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Fimbristylis dichotoma is found in temperate to tropical regions worldwide. It is one of the most widespread and weedy species of Fimbristylis, unquestionably with many races and forms. The two commonest forms in the United States often occur in mixed populations, one sort with inflorescence branches more ascending, inflorescence dense, habit lower, and leaves broader; the other sort usually taller, inflorescence more sparse, branches more widely spreading, and leaves more ascending and narrower. The abundance of such plants both in regions where rice originated and in regions where rice is, or was, introduced, indicates an Asian origin for such weeds. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 23. | FNA vol. 23, p. 125. | ||||
Parent taxa | Cyperaceae > Fimbristylis | Cyperaceae > Fimbristylis | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Scirpus puberulus | Scirpus dichotomus, F. annua var. diphylla, F. brizoides, F. diphylla subsp. diffusa, F. glauca, F. polymorpha, Scirpus diphyllus | ||||
Name authority | (Michaux) Vahl: Enum. Pl. 2: 289. (1805) | (Linnaeus) Vahl: Enum. Pl. 2: 287. (1805) | ||||
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