Pectis papposa |
Pectis rusbyi |
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chinchweed, common chinchweed, manybristle chinchweed |
Rusby's chinchweed, Rusby's cinchweed |
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Habit | Annuals, 1–30 cm (often forming rounded bushes); herbage spicy-scented. | Annuals, 5–50 cm (taprooted); herbage spicy-scented. | ||||
Stems | ascending, glabrous or puberulent. |
erect or ascending, glabrous or sparsely puberulent (in decurrent lines). |
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Leaves | linear, 10–60 × 1–2 mm, margins with 1–3 pairs of setae, faces glabrous (dotted on margins with round to oval oil-glands 0.3–0.5 mm). |
linear to narrowly elliptic, 10–50 × 1–5 mm, margins with 1–3 pairs of setae, faces glabrous or sparsely puberulent (dotted on margins with round oil-glands 0.2–0.7 mm). |
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Peduncles | 3–40 mm. |
20–80 mm. |
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Involucres | campanulate to cylindric. |
campanulate. |
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Ray florets | (7–)8(–10); corollas 3–8 mm. |
8(–13); corollas 5–11 mm. |
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Disc florets | 6–34; corollas 2–5.5 mm (weakly 2-lipped, glabrous or glandular-puberulent). |
(7–)20–55; corollas 3.5–5 mm (2-lipped). |
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Phyllaries | distinct, linear, 3–8 × 0.5–1.7 mm (dotted with 1–5 subterminal oil-glands plus 2–5 pairs of submarginal oil-glands). |
distinct, oblong or narrowly obovate, 4–7 × 1–2 mm (dotted with 0–2, subterminal oil-glands plus 2–4 pairs of inconspicuous, round to narrowly elliptic, submarginal oil-glands). |
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Heads | in congested or open, cymiform arrays. |
borne singly or in open, cymiform arrays. |
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Cypselae | 2–5.5 mm, strigillose to short-pilose (hair tips curled, bulbous); ray pappi usually coroniform, rarely of 1+ awns or bristles 1–4 mm; disc pappi usually of 16–24, subplumose bristles 1.5–4 mm, rarely coroniform. |
3–4.5 mm, strigillose or short-pilose; ray pappi of 1–4, antrorsely barbed awns 1–4 mm or coroniform; disc pappi of 15–30, antrorsely barbed bristles 2.5–5 mm or coroniform. |
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2n | = 24 (as P. palmeri). |
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Pectis papposa |
Pectis rusbyi |
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Phenology | Flowering Jul–Oct. | |||||
Habitat | Deserts, desert grasslands, arid scrub, dry woodlands | |||||
Elevation | 600–1600 m (2000–5200 ft) | |||||
Distribution |
AZ; CA; NM; NV; TX; UT; nw Mexico
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AZ; Mexico (Baja California Sur, Sinaloa, Sonora)
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Discussion | Varieties 2 (2 in the flora). Pectis papposa generally flowers following summer monsoon rains in the desert of southwestern United States and northern Mexico. In favorable years, it becomes an aspect dominant, coloring wide areas of the desert with its bright yellow heads. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Pectis rusbyi is much less common in Arizona than P. papposa var. papposa, with which it sometimes grows. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 21, p. 227. | FNA vol. 21, p. 227. | ||||
Parent taxa | Asteraceae > tribe Heliantheae > subtribe Pectidinae > Pectis | Asteraceae > tribe Heliantheae > subtribe Pectidinae > Pectis | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | P. palmeri | |||||
Name authority | Harvey & A. Gray: Mem. Amer. Acad. Arts, n. s. 4: 62. (1849) | Greene ex A. Gray: in A. Gray et al., Syn. Fl. N. Amer. 1(2): 361. (1884) | ||||
Web links |