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

bident d'Eaton, Eaton's beggar-ticks

Habit Annuals [perennials], (10–)30–60(–180+)[–250] cm. Annuals, (10–)25–70(–150) 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.

petioles (narrowly, if at all, winged) 10–35+ mm;

blades lance-ovate to lanceolate, (20–)35–100+ × 5–25+ mm, sometimes with 1–4 lobes near bases, bases cuneate, margins serrate, seldom ciliate, apices attenuate, faces glabrous.

Peduncles

10–20(–90) mm.

10–35+ mm.

Involucres

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

usually cylindric to campanulate, rarely hemispheric, (4–)8–10(–12) × (4–)7–9 mm.

Ray florets

0 or (3–)5–8+;

laminae whitish to pinkish [yellowish], 2–3 or 7–15+ mm.

usually 0, sometimes 1–3+;

laminae yellow-orange, 2–5(–10) mm.

Disc florets

20–40(–80+);

corollas yellowish, (2–)3–5 mm.

7–30+;

corollas yellowish, 2.5–3.5 mm.

Phyllaries

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

5–6, oblong to lance-ovate, 8–13 mm.

Calyculi

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

of (2–)3–5 ± erect, oblanceolate to linear, ± foliaceous bractlets or bracts 7–25(–70+) mm, margins sometimes obscurely ciliate, abaxial faces glabrous.

Heads

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

borne singly or in 2s or 3s.

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.

blackish to purplish or red-brown,± flattened, sometimes 3–4-angled, narrowly oblanceolate, outer 5.5–10 mm, inner 6.5–11 mm, margins barbed or ciliate (proximally antrorsely, distally retrorsely), apices ± truncate, faces ± 1-nerved, glabrous or sparsely setulose, often ± striate and/or tuberculate, pappi of 2–4(–5) erect to spreading, antrorsely or retrorsely barbed awns 3–4.5 mm.

2n

= 24, 36, 48, 72.

= 48.

Bidens pilosa

Bidens eatonii

Phenology Flowering year round. Flowering Sep–Oct.
Habitat Disturbed, wettish sites Borders of estuaries, marshes, tidal flats
Elevation 10–1900 m (0–6200 ft) 0–10 m (0–0 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]
from FNA
CT; MA; ME; NJ; NY; RI; NB; PE; QC
[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.)

Bidens eatonii may be better treated as part of B. tripartita.

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

Source FNA vol. 21, p. 211. FNA vol. 21, p. 218.
Parent taxa Asteraceae > tribe Heliantheae > subtribe Coreopsidinae > Bidens 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
B. amplissima, B. aristosa, B. aurea, B. beckii, B. bidentoides, B. bigelovii, B. bipinnata, B. cernua, B. connata, B. discoidea, B. frondosa, B. heterodoxa, B. heterosperma, B. hyperborea, B. laevis, B. lemmonii, B. leptocephala, B. mitis, B. pilosa, B. polylepis, B. tenuisecta, B. trichosperma, B. tripartita, B. vulgata
Synonyms B. alba, B. alba var. radiata, B. odorata, B. pilosa var. radiata B. eatonii var. fallax, B. eatonii var. illicita, B. eatonii var. interstes, B. eatonii var. kennebecensis, B. eatonii var. major, B. eatonii var. mutabilis, B. eatonii var. simulans
Name authority Linnaeus: Sp. Pl. 2: 832. (1753) Fernald: Rhodora 5: 92, plate 45, figs. 11–14. (1903)
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