Chylismia heterochroma |
Onagraceae tribe Onagreae |
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Shockley's evening-primrose |
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Habit | Herbs annual, glandular puberulent throughout, or glabrate and glaucous distally. | Herbs (annual or perennial), [shrubs]. |
Stems | several, 10–100 cm. |
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Leaves | primarily in poorly defined basal rosette, cauline greatly reduced when present; petiole 0.4–8 cm; blade unlobed, ovate to cordate, 2–11.5 × 1.4–5 cm, margins sinuate-dentate, brown oil cells prominently lining veins abaxially. |
alternate or basal; stipules absent. |
Racemes | erect, elongating in anthesis. |
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Flowers | opening at sunrise; buds without free tips; floral tube 2–5 mm, villous inside; sepals 1.5–3.5 mm; petals lavender, paler and often with flecks toward base, often yellow at very base, fading darker lavender, 2–6 mm; stamens unequal, filaments of antisepalous ones 1.8–3 mm, of antipetalous ones 1–2.5 mm, anthers 0.6–1 mm, glabrous or sparsely ciliate; style 4–7 mm, stigma surrounded by anthers at anthesis. |
usually actinomorphic, rarely slightly zygomorphic (in Oenothera), (3 or)4-merous; stamens 2 times as many, or rarely as many, as sepals; pollen usually shed in monads, rarely tetrads (Chylismia sect. Lignothera). |
Fruit | a dry capsule, usually dehiscent, sometimes indehiscent. |
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Capsules | erect, clavate, 7–13 mm; pedicel 2–5 mm. |
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Seeds | 1–1.2 mm. |
few to numerous, without hairs or wings, [very rarely with asymmetrical dry wing (Xylonagra)], or with dry (Oenothera), erose or smooth wing, or with thick, papillate wings (Chylismiella). |
2n | = 14. |
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Chylismia heterochroma |
Onagraceae tribe Onagreae |
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Phenology | Flowering May–Jun. | |
Habitat | Alluvial and rocky slopes. | |
Elevation | 600–2200 m. (2000–7200 ft.) | |
Distribution |
CA; NV
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North America; Mexico; Central America; South America; West Indies |
Discussion | Chylismia heterochroma is known from Churchill and Lander counties, Nevada, south to Lincoln and southern Nye counties, Nevada, to adjacent California (Mono Lake, Mono County, and central Inyo counties). P. H. Raven (1962, 1969) determined this species to be self-compatible and autogamous. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Genera 13, species 265 (12 genera, 199 species in the flora). Onagreae account for more than half the total genera in Onagraceae and diversified from a center in southwestern North America (L. Katinas et al. 2004). Delimitation of the tribe by W. L. Wagner et al. (2007) differs from previous ones by the exclusion of Gongylocarpus, now in its own tribe, by the segregation of eight genera (Camissoniopsis, Chylismia, Chylismiella, Eremothera, Eulobus, Neoholmgrenia, Taraxia, and Tetrapteron) from Camissonia, and by the inclusion of three previously separate genera (Calylophus, Gaura, and Stenosiphon) in Oenothera. Within the branch of the family that lacks stipules (Gongylocarpeae, Epilobieae, and Onagreae), the last two tribes form a clade that has very strong molecular support (R. A. Levin et al. 2003, 2004), but no obvious morphological synapomorphy. The clade may be defined by a cytogenetic change from the base chromosome number of x = 11 found in Circaeeae, Gongylocarpeae, and Lopezieae, to x = 18 in Epilobieae, and x = 7 in Onagreae; however, these changes could also have occurred independently. Other than the new chromosome number x = 7, the only apparent morphological synapomorphy for Onagreae alone is pollen with prominent apertural protrusions (J. Praglowski et al. 1987, 1989), a character state also found in Circaeeae (Praglowski et al. 1994). The monophyly of Onagreae has moderate (Levin et al. 2004) to strong support (V. S. Ford and L. D. Gottlieb 2007). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | Onagraceae > subfam. Onagroideae > tribe Onagreae > Chylismia > sect. Chylismia | Onagraceae > subfam. Onagroideae |
Sibling taxa | ||
Subordinate taxa | ||
Synonyms | Oenothera heterochromas., Camissonia heterochroma, C. heterochroma var. monoensis, O. heterochroma subsp. monoensis, O. heterochroma var. monoensis | |
Name authority | (S. Watson) Small: Bull. Torrey Bot. Club 23: 193. (1896) — (as Chylisma) | Dumortier: Fl. Belg., 89. (1827) |
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