Bidens tripartita |
Bidens discoidea |
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bident à trois divisions, three-lobed beggar-ticks, three-lobed beggars-ticks, three-part beggarticks, threelobe beggarticks, tickseed |
bident discoïde, discoid beggarticks, small beggar-ticks, swamp beggar-ticks |
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Habit | Annuals, (5–)20–70(–200) cm. | Annuals, (10–)20–60(–180) cm. |
Leaves | sessile or petioles 5–15(–35+) mm (± winged); blades ± elliptic to ovate or lanceolate, 40–80(–150+) × 15–40(–60+) mm, sometimes laciniately 1-pinnatisect with 1–4+ lobes near bases, bases cuneate, margins entire or dentate to serrate, usually ciliate, apices acute to acuminate, faces glabrous or hirtellous. |
petioles 10–40(–60) mm; blades deltate to lance-ovate overall, 30–80(–100+) × 10–30(–80+) mm, usually 3-foliolate, leaflets petiolulate, lance-ovate to lanceolate, (10–)20–50(–100) × 5–20(–40) mm, bases cuneate, ultimate margins usually serrate, sometimes ciliate, apices acuminate to attenuate, faces glabrous or hirtellous. |
Peduncles | 10–40(–80) mm. |
10–20(–50+) mm. |
Involucres | campanulate to hemispheric or broader, (4–)5–7(–12) × (3–)6–12(–15+) mm. |
± hemispheric, 4–5(–7) × 4–6(–9) mm. |
Ray florets | usually 0, sometimes 1–5; laminae orange yellowish, 4–8 mm. |
0. |
Disc florets | (5–)20–60(–150+); corollas pale yellow to orange, (2–)3–4 mm (gradually ampliate, anthers usually pale). |
(10–)15–20+; corollas ± orange, 1.5–2 mm. |
Phyllaries | (6–)7–8(–13), elliptic-ovate to lance-ovate, (4–)6–9(–12) mm. |
5–7, oblong to lanceolate, 4–6+ mm. |
Calyculi | of (2–)6–7(–10) ± spreading, oblanceolate or lanceolate to linear, ± foliaceous bractlets or bracts 7–35(–60) mm, margins (entire or serrate) sometimes sparsely ciliate, abaxial faces hispidulous near bases, distally glabrous. |
of (3–)4(–5+) ± appressed, spatulate to linear, seldom foliaceous bractlets or bracts (3–)12–25 mm, margins seldom ciliate, abaxial faces usually glabrous. |
Heads | borne singly or in 2s or 3s. |
usually borne singly, sometimes in 2s or 3s. |
Cypselae | blackish to purplish or brown, ± flattened, sometimes weakly 3(–4)-angled, usually cuneate to linear, outer (3–)6–7(–10) mm, inner (4–)6–9(–11) mm, margins proximally antrorsely to patently, distally retrorsely, barbed, apices ± truncate to concave, faces ± 1-nerved, usually smooth, seldom notably tuberculate, glabrous or sparsely strigillose; pappi 0, or of (1–)3–3(–4+) ± erect to spreading, retrorsely barbed awns (0.2–)2–3(–6) mm. |
blackish to red-brown or stramineous, ± flattened, linear to narrowly cuneate, outer 3–5 mm, inner 4–6+ mm, margins not distinctly ciliate, apices ± truncate to concave, faces ± tuberculate, antrorsely strigillose; pappi of 2 ± erect, antrorsely barbed or smooth awns (0.2–)1–2.4 mm. |
2n | = 48. |
= 24. |
Bidens tripartita |
Bidens discoidea |
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Phenology | Flowering Aug–Oct. | Flowering Aug–Oct(–Nov). |
Habitat | Marshes and other wet sites | Ponds, swamps, other relatively wet sites |
Elevation | 10–1700 m (0–5600 ft) | 10–300 m (0–1000 ft) |
Distribution |
AK; AL; CA; CO; CT; DC; DE; GA; IA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; QC; Europe; Asia; n Africa [Introduced in Pacific Islands, Australia]
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AL; AR; CT; DC; DE; FL; GA; IA; IL; IN; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; NH; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; VT; WI; WV; NB; NS; ON; QC
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Discussion | Plants with cypsela mid-nerves strongly developed (cypselae more or less strongly 4-angled and, often, tuberculate) that are treated below as Bidens connata have been included in B. tripartita, perhaps rightly so. And some botanists have included (or advocated inclusion of) B. eatonii, B. heterodoxa, and/or B. infirma in B. tripartita, as well, perhaps rightly so. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Bidens discoidea is not nearly as variable morphologically as the closely related B. vulgata or B. frondosa. It differs from B. frondosa in having smaller heads, cypselae with shorter, antrorsely barbed awns, fewer phyllaries and flowers per head, sparse indument, and leaves with fewer, more acuminate leaflets. Both B. discoidea and B. frondosa differ from B. vulgata in texture of flowers, in heads, and in shapes and surfaces of cypselae (M. L. Roberts 1982, 1983; M. G. Hickler 1999). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 21, p. 217. | FNA vol. 21, p. 211. |
Parent taxa | Asteraceae > tribe Heliantheae > subtribe Coreopsidinae > Bidens | Asteraceae > tribe Heliantheae > subtribe Coreopsidinae > Bidens |
Sibling taxa | ||
Synonyms | B. comosa | Coreopsis discoidea |
Name authority | Linnaeus: Sp. Pl. 2: 831. (1753) | (Torrey & A. Gray) Britton: Bull. Torrey Bot. Club 20: 281. (1893) |
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