Bidens laevis |
Bidens aristosa |
|
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bur-marigold, smooth beggar-ticks, smooth beggartick |
bearded beggarticks, long-bract beggar-ticks, midwestern beggar-ticks, tickseed sunflower |
|
Habit | Annuals (sometimes persisting), (10–)20–60(–120+) cm. | Annuals, (15–)30–60(–150) cm. |
Leaves | (sometimes in 3s or 4s) sessile; blades obovate or elliptic to lanceolate or linear, (20–)50–100(–160+) × (5–)10–25(–40+) mm, bases cuneate to rounded, margins usually coarsely dentate to serrate, sometimes ciliate, apices acute to acuminate, faces glabrous. |
petioles 10–30 mm; blades lanceolate to lance-linear overall, 30–80(–150) × 10–30(–50) mm, usually laciniately pinnatisect, primary lobes 3–7+, 15–60+ × 2–20 mm, bases cuneate, ultimate margins laciniate to serrate, ciliate, apices acuminate, faces glabrous or sparsely scabrellous. |
Peduncles | (10–)20–60 mm. |
(10–)30–80+ mm. |
Involucres | turbinate to hemispheric or broader, (4–)6–8(–10+) × 8–12+ mm. |
± hemispheric or broader, 6–8(–12) × 10–15 mm. |
Ray florets | usually 7–8, rarely 0; laminae orange-yellow, (10–)15–25(–30) mm. |
(5–)8–10+; laminae yellow, 10–25 mm. |
Disc florets | (25–)60–100(–150+); corollas yellow to orange-yellow, 3–6.5 mm. |
(12–)20–40+; corollas yellowish, 2–3+ mm. |
Phyllaries | 8–12, ovate or obovate to lance-oblong, (4–)6–8(–10+) mm (tips often orange to purplish, as are tips of paleae). |
7–8(–13), lance-ovate to lance-linear, 6–8(–12) mm. |
Calyculi | of 5–7(–9+) erect or spreading to reflexed, oblanceolate or lanceolate to linear, often foliaceous bractlets or bracts (6–)10–12(–20+) mm, margins usually ciliate, abaxial faces glabrous or bases hispidulous. |
of 8–12(–16) usually spreading to reflexed, linear, seldom foliaceous bractlets (4–)5–7(–12) mm, margins entire, ciliate, abaxial faces glabrous or ± scabrellous. |
Heads | (erect at flowering, sometimes nodding in fruit) borne singly or in open, ± corymbiform arrays. |
in ± corymbiform arrays. |
Cypselae | blackish, red-brown, or stramineous, obcompressed, flattened or unequally 3–4-angled, ± cuneate, outer 6–8 mm, inner 8–10 mm, margins retrorsely ciliate or barbed, apices ± truncate to convex, faces ± 1-nerved, ± striate, glabrous; pappi of 2–4 ± erect, retrorsely barbed awns 3–5 mm. |
red-brown to blackish, ± flattened (unequally 3–4-angled), broadly cuneate, outer (4–)5–6 mm, inner 5–7 mm (lengths mostly 1.5–2.5 times widths), margins (± corky-winged) patently to antrorsely barbed, apices truncate to concave, faces weakly striate, sometimes tuberculate, glabrous or sparsely strigillose; pappi 0, or of 2(–4) spreading to divergent, antrorsely or retrorsely barbed awns (0.5–)2–4(–6) mm. |
2n | = 22, 24. |
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Bidens laevis |
Bidens aristosa |
|
Phenology | Flowering Aug–Oct(–Dec). | Flowering Aug–Oct(–Nov). |
Habitat | Meadows, marshes, and margins of pools, streams, estuaries | Marshes, meadows, pine forests, disturbed sites |
Elevation | 0–2800 m (0–9200 ft) | 0–300 m (0–1000 ft) |
Distribution |
AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IN; KY; LA; MA; MD; ME; MO; MS; NC; NH; NJ; NM; NV; NY; OH; PA; RI; SC; TN; TX; VA; WV; Mexico; Central America; South America [Introduced Pacific Islands (Hawaii)]
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AL; AR; DC; IL; IN; KY; LA; MD; MI; MN; MO; NC; SC; TN; TX; VA; ON
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Discussion | Bidens laevis and B. cernua are similar in gross appearance; specimens of one are sometimes misidentified as the other. Perhaps they represent extremes of a single species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 21, p. 215. | FNA vol. 21, p. 214. |
Parent taxa | Asteraceae > tribe Heliantheae > subtribe Coreopsidinae > Bidens | Asteraceae > tribe Heliantheae > subtribe Coreopsidinae > Bidens |
Sibling taxa | ||
Synonyms | Helianthus laevis, B. chrysanthemoides, B. helianthoides, B. nashii, B. quadriaristata | Coreopsis aristosa, B. aristosa var. fritcheyi, B. aristosa var. mutica |
Name authority | (Linnaeus) Britton: Prelim. Cat., 29. (1888) | (Michaux) Britton: Bull Torrey Bot. Club 20: 281. (1893) |
Web links |