Pectis longipes |
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longstalk chinchweed, longstalk cinchweed, mat cinchweed |
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Habit | Perennials, 8–25 cm (rhizomes branched, 1–10 mm diam.); herbage lemon-scented or spicy-scented. |
Stems | ascending to erect (very leafy), glabrous. |
Leaves | linear to linear-oblanceolate, 10–55 × 1–3 mm, margins with 1–4 pairs of setae, faces glabrous (conspicuously dotted on margins with round oil-glands 0.3–0.5 mm). |
Peduncles | (30–)50–160 mm. |
Involucres | campanulate. |
Ray florets | (8–)13(–15); corollas 8–12 mm. |
Disc florets | 25–50; corollas 4–6 mm (2-lipped). |
Phyllaries | distinct, linear, linear-oblanceolate, or linear-elliptic, 5–8 × 0.7–2 mm (dotted with 1–3, swollen, subterminal oil-glands 0.3–0.4 mm plus 1–3 pairs of narrow, submarginal oil-glands). |
Heads | borne singly. |
Cypselae | 2.5–4.5 mm, strigillose (hairs tips acute or blunt); ray pappi of 1–2 awns 3–3.5 mm; disc pappi of 2–30 unequal bristles 3–5 mm. |
2n | = 24, 48. |
Pectis longipes |
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Phenology | Flowering Apr–Nov. |
Habitat | Grasslands, oak-juniper-mesquite woodlands |
Elevation | 900–1700 m (3000–5600 ft) |
Distribution |
AZ; NM; Mexico (Chihuahua, Durango, Sonora)
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Discussion | Pectis longipes has been listed from Texas in floras; I have seen no collections from that state. Pectis longipes comprises two cytological races. Diploid, spicy-scented plants occur throughout the range. In southern Arizona, the diploid race is broadly sympatric but locally allopatric with a tetraploid, lemon-scented race. The tetraploid race is nested within the range of the diploids. The races are easily separable by odor, and although they are very similar morphologically, they can be separated also by statistically significant differences in floral dimensions and pollen size (M. A. Luckow 1983). Based upon those minute differences, the type collection is diploid. Because the races are so similar morphologically and because so many of the specimens of P. longipes in herbaria bear no indication of odor, I chose not to give the cytological races formal recognition. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 21, p. 226. |
Parent taxa | |
Sibling taxa | |
Name authority | A. Gray: Smithsonian Contr. Knowl. 5(6): 69. (1853) |
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