The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

bident poilu, cobbler's pegs, common beggar-ticks, hairy beggar-ticks, Spanish needle

Habit 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.

Peduncles

10–20(–90) mm.

Involucres

turbinate to campanulate, 5–6 × (6–)7–8 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.

Phyllaries

(7–)8–9(–13), lanceolate to oblanceolate, 4–6 mm.

Calyculi

(6–)7–9(–13) ± appressed, spatulate to linear bractlets (3–)4–5 mm, margins ciliate, abaxial faces usually hispidulous to puberulent.

Heads

usually borne singly, sometimes in open, ± corymbiform arrays.

Cypselae

outer red-brown, ± 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.

Bidens pilosa

Phenology Flowering year round.
Habitat Disturbed, wettish sites
Elevation 10–1900 m (0–6200 ft)
Distribution
from FNA
AL; AZ; CA; CT; FL; GA; KY; LA; MA; MD; MO; MS; NC; NM; PA; SC; TX; ON; QC; Mexico; Central America [Introduced, Europe]
[WildflowerSearch map]
[BONAP county map]
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.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 21, p. 211.
Parent taxa Asteraceae > tribe Heliantheae > subtribe Coreopsidinae > Bidens
Sibling taxa
B. amplissima, B. aristosa, B. aurea, B. beckii, B. bidentoides, B. bigelovii, B. bipinnata, B. cernua, B. connata, B. discoidea, B. eatonii, B. frondosa, B. heterodoxa, B. heterosperma, B. hyperborea, B. laevis, B. lemmonii, B. leptocephala, B. mitis, B. polylepis, B. tenuisecta, B. trichosperma, B. tripartita, B. vulgata
Synonyms B. alba, B. alba var. radiata, B. odorata, B. pilosa var. radiata
Name authority Linnaeus: Sp. Pl. 2: 832. (1753)
Web links