Chylismia walkeri |
Chylismia exilis |
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Walker's evening-primrose, Walker's sun-cup |
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Habit | Herbs annual or short-lived perennial, villous, usually densely so proximally, less dense to glabrate distally, sometimes hairs somewhat appressed and shorter on leaves, also sometimes glandular puberulent on distal parts. | Herbs annual, glandular puberulent and sparsely villous. | ||||
Stems | slender, unbranched or branched from base, 10–60 cm. |
slender, unbranched or branched, 10–20 cm. |
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Leaves | in basal rosette and/or cauline, often purple-dotted, 2–22 × 0.4–3.5 cm; petiole 0.4–8 cm; blade pinnately lobed, sometimes lateral lobes greatly reduced or absent and blade reduced to terminal lobe only, terminal lobe oblong or cordate to ovate, 1–5 × 0.5–3.2 cm, margins serrate, brown oil cells prominently lining veins abaxially. |
primarily cauline; petiole 0.3–1.8 cm; blade unlobed, narrowly ovate to elliptic, 0.3–2 × 0.3–1 cm, margins entire or inconspicuously denticulate, brownish oil cells lining veins abaxially. |
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Racemes | erect, elongating after anthesis. |
erect, elongating in fruit. |
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Flowers | opening at sunrise; buds individually reflexed, with apical free tips less than 1 mm; floral tube 0.5–1.5 mm, glabrous or sparsely villous inside; sepals 1.5–5 mm; petals bright yellow, fading pale orange or lavender, 1–6 mm; stamens unequal, filaments of antisepalous stamens 1–3 mm, those of antipetalous ones 0.3–2 mm, anthers 0.5–2 mm, glabrous or sparsely ciliate; style 1.5–6 mm, stigma surrounded by anthers at anthesis. |
opening at sunrise; buds without free tips; floral tube 0.4–0.5 mm, glabrous inside; sepals 1–1.2 mm; petals yellow, fading pale lavender, 1–1.5 mm; stamens 4 (or 8), antisepalous, filaments 0.5 mm, anthers 0.5–0.7 mm, glabrous, when 8, then antipetalous ones smaller and abortive; style 1.5 mm, stigma surrounded by anthers at anthesis. |
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Capsules | spreading or ascending, oblong-cylindrical, 11–45 mm; pedicel 5–30 mm. |
spreading or reflexed, clavate, 4–10 mm; pedicel 3–9 mm. |
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Seeds | 0.6–1.2 mm. |
0.8 mm. |
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2n | = 14. |
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Chylismia walkeri |
Chylismia exilis |
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Phenology | Flowering Apr–Jun. | |||||
Habitat | Calcareous sand, gypseous clay flats, juniper woodlands. | |||||
Elevation | 1000–1900 m. (3300–6200 ft.) | |||||
Distribution | sw United States
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AZ; UT |
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Discussion | Subspecies 2 (2 in the flora). P. H. Raven (1962, 1969) determined this species to be self-incompatible and primarily autogamous. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Chylismia exilis, known from Kane and San Juan counties in Utah and northern Coconino and Mohave counties in Arizona, is cryptic due to its small size. It may not be as rare as assumed, since it is difficult to spot in the field. P. H. Raven (1962, 1969) determined this species to be self-compatible and autogamous. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 10. | FNA vol. 10. | ||||
Parent taxa | Onagraceae > subfam. Onagroideae > tribe Onagreae > Chylismia > sect. Chylismia | Onagraceae > subfam. Onagroideae > tribe Onagreae > Chylismia > sect. Chylismia | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Camissonia walkeri, Oenothera walkeri | Oenothera exilis, Camissonia exilis | ||||
Name authority | A. Nelson: Bot. Gaz. 56: 66. (1913) — (as Chylisma) | (P. H. Raven) W. L. Wagner & Hoch: Syst. Bot. Monogr. 83: 207. (2007) | ||||
Web links |