Pectis papposa |
Pectis humifusa |
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chinchweed, common chinchweed, manybristle chinchweed |
yerba de San Juan |
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Habit | Annuals, 1–30 cm (often forming rounded bushes); herbage spicy-scented. | Annuals or perennials, 2–25 cm (across; bases often ± woody); herbage not scented. | ||||
Stems | ascending, glabrous or puberulent. |
prostrate (mat-forming, densely leafy), 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). |
oblong-oblanceolate to obovate, 3–17 × 1.5–4 mm wide, margins with 2–6 pairs of setae 1–2 mm, faces glabrous (dotted with scattered, round oil-glands 0.1–0.2 mm). |
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Peduncles | 3–40 mm. |
1–12 mm. |
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Involucres | campanulate to cylindric. |
campanulate. |
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Ray florets | (7–)8(–10); corollas 3–8 mm. |
5; corollas 3.5–5 mm. |
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Disc florets | 6–34; corollas 2–5.5 mm (weakly 2-lipped, glabrous or glandular-puberulent). |
12–21; corollas 2.5–3.5 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, obovate, 4.5–6 × 2–4 mm (faces densely dotted with scattered, circular oil-glands 0.05–0.2 mm). |
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Heads | in congested or open, cymiform arrays. |
borne singly or in congested, (leafy) 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. |
2.5–4 mm, mostly puberulent (ray cypselae abaxially glabrous); ray pappi of 2–3 slender, aristate scales 1.5–2.5 mm plus 2–10 lacerate scales or bristles; disc pappi of 4–15, antrorsely scabrid bristles or aristate scales 2–3 mm plus 0–15 bristles or scales. |
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2n | = 72. |
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Pectis papposa |
Pectis humifusa |
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Phenology | Flowering year round. | |||||
Habitat | Sandy soils | |||||
Elevation | 0–10 m (0–0 ft) | |||||
Distribution |
AZ; CA; NM; NV; TX; UT; nw Mexico
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FL; West Indies (Puerto Rico, Lesser Antilles); South America (Suriname) |
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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 humifusa has been reported once from Florida (D. J. Keil 1975c), where it is probably adventive. In the Lesser Antilles, it occurs most frequently in the salt spray zone near the seashore; on some islands, it occurs inland as well. (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. 225. | ||||
Parent taxa | Asteraceae > tribe Heliantheae > subtribe Pectidinae > Pectis | Asteraceae > tribe Heliantheae > subtribe Pectidinae > Pectis | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Name authority | Harvey & A. Gray: Mem. Amer. Acad. Arts, n. s. 4: 62. (1849) | Swartz: Prodr., 114. (1788) | ||||
Web links |