Bidens laevis |
Bidens hyperborea |
|
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bur-marigold, smooth beggar-ticks, smooth beggartick |
bident hyperboréal, estuary beggarticks, northern beggar-ticks |
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Habit | Annuals (sometimes persisting), (10–)20–60(–120+) cm. | Annuals, (5–)10–30(–70+) 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. |
sessile or petioles 5–25 mm (± winged); blades oblanceolate to linear, 15–40(–100+) × (3–)6–10(–15+) mm, bases cuneate, margins entire or ± serrate, sometimes ciliate, apices rounded or obtuse to attenuate, faces glabrous. |
Peduncles | (10–)20–60 mm. |
10–60 mm. |
Involucres | turbinate to hemispheric or broader, (4–)6–8(–10+) × 8–12+ mm. |
usually ± campanulate to cylindric, sometimes ± hemispheric, 5–7(–9) × (4–)7–10 mm. |
Ray florets | usually 7–8, rarely 0; laminae orange-yellow, (10–)15–25(–30) mm. |
0 or 3–7; laminae pale yellow, 4–12 mm. |
Disc florets | (25–)60–100(–150+); corollas yellow to orange-yellow, 3–6.5 mm. |
15–30(–60); corollas yellow (often orange-tipped), 3–4 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). |
6–8(–12), oblong, 6–11 mm (tips usually yellow, as are tips of paleae). |
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 2–3(–9) erect, oblanceolate to lance-linear (± foliaceous) bractlets or bracts (6–)10–20(–75+) mm, margins usually ciliolate, abaxial faces glabrous. |
Heads | (erect at flowering, sometimes nodding in fruit) borne singly or in open, ± corymbiform arrays. |
borne singly or in 2s or 3s. |
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. |
blackish to olive, flattened, narrowly cuneate, outer 4–9 mm, inner 5–10 mm, margins retrorsely barbed, apices ± truncate to convex, faces ± 1-nerved, ± striate, glabrous; pappi of (2–)3–4 ± erect, retrorsely barbed awns 2–5 mm. |
2n | = 22, 24. |
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Bidens laevis |
Bidens hyperborea |
|
Phenology | Flowering Aug–Oct(–Dec). | Flowering Aug–Oct. |
Habitat | Meadows, marshes, and margins of pools, streams, estuaries | Marshes, borders of estuaries |
Elevation | 0–2800 m (0–9200 ft) | 0–10 m (0–0 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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MA; ME; NH; NY; NB; NS; NU; ON; QC
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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. 216. |
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 | B. hyperborea var. arcuans, B. hyperborea var. cathancensis, B. hyperborea var. colpophila, B. hyperborea var. gaspensis, B. hyperborea var. svensonii |
Name authority | (Linnaeus) Britton: Prelim. Cat., 29. (1888) | Greene: Pittonia 4: 257. (1901) |
Web links |