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

slim-lobe beggarticks, slim-lobed beggar-ticks

Habit Annuals [perennials], (10–)30–60(–180+)[–250] cm. Annuals, (10–)20–40 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 5–40 mm;

blades rounded-deltate to ovate overall, 20–50+ × 15–35+ mm, (1–)2–3-pinnatisect, ultimate lobes ± linear, (2–)5–15+ × (0.5–)2–3+ mm, bases ± cuneate, ultimate margins entire, sometimes ciliolate, apices acute to attenuate, faces usually glabrous, sometimes hispidulous.

Peduncles

10–20(–90) mm.

20–30(–80) mm.

Involucres

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

campanulate to hemispheric or broader, (5–)6–7 × 4–8 mm.

Ray florets

0 or (3–)5–8+;

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

0 or 3–6;

laminae yellow, 4–6 mm.

Disc florets

20–40(–80+);

corollas yellowish, (2–)3–5 mm.

(5–)12–20(–45);

corollas yellow, 2–3 mm.

Phyllaries

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

8, lance-linear, 5–7 mm.

Calyculi

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

of 6–12 ± appressed, linear bractlets 5–7 mm, margins scabro-ciliate, abaxial faces usually pilosulous to hirsutulous, rarely glabrous.

Heads

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

usually borne singly, sometimes 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.

outer red-brown, flat or weakly 4-angled, linear, 6–8 mm, margins not ciliate, apices somewhat attenuate, faces obscurely 2-grooved, often tuberculate, glabrous or ± strigillose;

inner similar, blackish (sometimes with pale tips), ± equally 4-angled, linear-fusiform, 8–15 mm, margins not ciliate, apices attenuate, faces 2-grooved, glabrous or, toward tips, strigillose;

pappi of 2(–3), spreading to divergent, retrorsely barbed awns (1–)1.5–3 mm.

2n

= 24, 36, 48, 72.

Bidens pilosa

Bidens tenuisecta

Phenology Flowering year round. Flowering (Jul–)Aug–Sep(–Oct).
Habitat Disturbed, wettish sites Meadows, along streams
Elevation 10–1900 m (0–6200 ft) 1800–2600 m (5900–8500 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
AZ; CO; ID; NM; UT; Mexico (Chihuahua)
[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.)

Reports of Bidens tenuisecta from Maryland, Massachusetts, and New York may be based on ephemeral introductions.

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

Source FNA vol. 21, p. 211. FNA vol. 21, p. 210.
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. eatonii, B. frondosa, B. heterodoxa, B. heterosperma, B. hyperborea, B. laevis, B. lemmonii, B. leptocephala, B. mitis, B. pilosa, B. polylepis, 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) A. Gray: Mem. Amer. Acad. Arts, n. s. 4: 86. (1849)
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