Bidens pilosa

Linnaeus

Sp. Pl. 2: 832. 1753.

Common names: Bident poilu
Synonyms: Bidens alba (Linnaeus) de Candolle Bidens alba var. radiata (Schultz-Bipontinus) R. E. Ballard Bidens odorata Bidens pilosa var. radiata (Schultz-Bipontinus) Schultz-Bipontinus
Treatment appears in FNA Volume 21. Treatment on page 211. Mentioned on page 207.

Annuals [perennials], (10–) 30–60 (–180+) [–250] cm. Leaves: petioles 10–30 (–70) mm; blades either ovate to lanceolate, 30–70 (–120) × 12–18 (–45) mm, or 1-pinnately lobed, primary lobes 3–7, ovate to lanceolate [linear], (10–) 25–80+ × (5–) 10–40+ mm [blades 2 (–3) -pinnatisect], bases truncate to cuneate, ultimate margins serrate or entire, usually ciliate, apices acute to attenuate, faces pilosulous to sparsely hirtellous or glabrate. Heads usually borne singly, sometimes in open, ± corymbiform arrays. Peduncles 10–20 (–90) mm. Calyculi (6–) 7–9 (–13) ± appressed, spatulate to linear bractlets (3–) 4–5 mm, margins ciliate, abaxial faces usually hispidulous to puberulent. Involucres turbinate to campanulate, 5–6 × (6–) 7–8 mm. Phyllaries (7–) 8–9 (–13), lanceolate to oblanceolate, 4–6 mm. Ray-florets 0 or (3–) 5–8+; laminae whitish to pinkish [yellowish], 2–3 or 7–15+ mm. Disc-florets 20–40 (–80+); corollas yellowish, (2–) 3–5 mm. Cypselae: outer redbrown, ± flat, linear to narrowly cuneate, (3–) 4–5+ mm, margins antrorsely hispidulous, apices ± truncate or somewhat attenuate, faces obscurely 2-grooved, sometimes tuberculate-hispidulous; inner blackish, ± equally 4-angled, linear-fusiform, 7–16 mm, margins antrorsely hispidulous, apices ± attenuate, faces 2-grooved, tuberculate-hispidulous to sparsely strigillose; pappi 0, or of 2–3 (–5), erect to divergent, retrorsely barbed awns (0.5–) 2–4 mm. 2n = 24, 36, 48, 72.


Phenology: Flowering year round.
Habitat: Disturbed, wettish sites
Elevation: 10–1900 m

Distribution

V21-513-distribution-map.gif

Introduced; Ont., Que., Ala., Ariz., Calif., Conn., Fla., Ga., Ky., La., Md., Mass., Miss., Mo., N.Mex., N.C., Pa., S.C., Tex., Mexico, Central America, Europe

Discussion

R. Ballard (1986) adopted a narrower circumscription of Bidens pilosa than that used here. He used: B. pilosa for plants with outer phyllaries 7–10, ray florets usually 0 (when present, laminae 2–3 mm), disc florets 35–75, pappi of 3(–5) awns 1–3 mm, and 2n = 72; B. alba for plants with outer phyllaries (8–)12(–16), ray florets 5–8 (laminae 5–16 mm), pappi of 2 awns 1–2 mm, and 2n = 48; and B. odorata for plants with outer phyllaries (6–)8(–12), ray florets 5–8 (laminae 3–18 mm), disc florets 12–61, pappi 0, or of 1–2 awns 1–3 mm, and 2n = 24.

Lower Taxa

None.
... more about "Bidens pilosa"
72 +, 48 +, 36 +  and 24 +
usually hispidulous +  and puberulent +
not tailed +, rounded +  and obtuse +
dark +  and pale +
connate +  and distinct +
subequal +
scarious +
usually ovate +  and lanceolate +
usually deltate +  and lanceolate +
indeterminate +  and determinate +
John L. Strother +  and Ronald R. Weedon +
Linnaeus +
ciliate +  and barbellate +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
2 +  and 3 +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
truncate +  and cuneate +
compound +  and simple +
7 cm70 mm <br />0.07 m <br /> (12 cm120 mm <br />0.12 m <br />) +
1.8 cm18 mm <br />0.018 m <br /> (4.5 cm45 mm <br />0.045 m <br />) +
3 cm30 mm <br />0.03 m <br /> (7 cm70 mm <br />0.07 m <br />) +
lobed;ovate;lanceolate +
12mm;18mm +
winged;ribbed;winged;ribbed +
tuberculate +  and rugose +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
erect +  and spreading or reflexed +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
barbellulate +  and barbellate +
Bident poilu +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
subterete +, linear-fusiform +, 4-angled +, cuneate +  and oblanceolate or obovate +
fertile +  and bisexual +
fertile +  and bisexual +
sessile +  and petiolate +
Ont. +, Que. +, Ala. +, Ariz. +, Calif. +, Conn. +, Fla. +, Ga. +, Ky. +, La. +, Md. +, Mass. +, Miss. +, Mo. +, N.Mex. +, N.C. +, Pa. +, S.C. +, Tex. +, Mexico +, Central America +  and Europe +
10–1900 m +
tuberculate-hispidulous +  and sparsely strigillose +
tuberculate +, striate +  and scabrellous +
linear-fusiform;4-angled;ovate;orbiculate;oblong;linear;cuneate +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Disturbed, wettish sites +
discoid +  and radiate +
disciform +  and discoid +
indeterminate +
homogamous +  and heterogamous +
each +  and sessile +
linear-fusiform +  and 4-angled +
0.7 cm7 mm <br />0.007 m <br /> (1.6 cm16 mm <br />0.016 m <br />) +
0.6 cm6 mm <br />0.006 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
turbinate;campanulate +
0.7 cm7 mm <br />0.007 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
whitish +  and pinkish +
7-15+ mm (?) +, 2 (?) +  and 3 (?) +
sessile +  and petiolate +
whorled +  and opposite +
deltate +
hispidulous +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
linear +  and narrowly cuneate +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
2-carpellate +
less flat;slightly navicular +
persistent +
of 1-2 , smooth to ciliate or barbed awns or scales +  and coroniform +
2 cm20 mm <br />0.02 m <br /> (9 cm90 mm <br />0.09 m <br />) +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
3 cm30 mm <br />0.03 m <br /> (7 cm70 mm <br />0.07 m <br />) +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
Flowering year round. +
connate +  and distinct +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
1 cm10 mm <br />0.01 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
2.5 cm25 mm <br />0.025 m <br /> (8 cm80 mm <br />0.08 m <br />) +
ovate;lanceolate +
styliferous +  and neuter +
bearing subulate enations +, hairy +  and bristly +
convex;flat +
ballard1986a +
exalbuminous +
appendaged +  and truncate +
hirsutulous +  and glabrous +
papillate +
Bidens alba +, Bidens alba var. radiata +, Bidens odorata +  and Bidens pilosa var. radiata +
Bidens pilosa +
species +
toothed +, serrate +, laciniate +  and dentate +
60 cm600 mm <br />0.6 m <br /> (180 cm1,800 mm <br />1.8 m <br />) +
30 cm300 mm <br />0.3 m <br /> (60 cm600 mm <br />0.6 m <br />) +
shrub +  and subshrub +