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Oenothera albicaulis
(White-stemmed Evening
Primrose) Onagraceae (Evening Primrose Family) Semi-desert, foothills.
Openings, sand. Spring. This low-to-the-ground annual or winter annual is fairly common and its very large white flowers quickly catch attention. Basal leaves range from entire to deeply dissected (pinnatifid) and stem leaves are often progressively smaller and also deeply dissected. Frederick Pursh named this plant in his 1814 Flora Americana from a specimen collected by John Bradbury in the upper Louisiana Territory. "Albicaulis" is Latin for "white-stemmed". |
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Oenothera caespitosa
(Matted Evening
Primrose) Onagraceae (Evening Primrose Family) Semi-desert, foothills,
montane. Disturbed areas, openings, sand. Spring, summer. This is a very common, wide ranging, Evening Primrose with a number of common varieties. It has very large white flowers, spreads by underground roots, and is often abundant in large colonies on steep dry slopes and sandy soils. The entire plant is quite low to the ground, and the flower, disproportionately large for the size of the rest of the plant, often touches the ground. Leaf length and depth of serrations and teeth varies. Flowers often open in the evening and wither to pink with the sun and heat of the next afternoon. "Caespitosa", "growing in tufts", refers to the dense tufts of basal leaves and stems. Thomas Nuttall collected this plant along the banks of the Missouri in South Dakota in 1811 and named it in 1813. |
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Oenothera coronopifolia
(Cut-leaf Evening Primrose) Onagraceae (Evening Primrose Family) Foothills, montane. Woodlands, openings.
Spring, summer. The very finely cut leaves, large white
flowers, and spreading clusters of this slender Oenothera distinguish it. Oenothera coronopifolia often grows in colonies of many plants; areas of the foothills
would have this as a common plant if it were not for cows, alfalfa
fields, and lawn mowers.
"Coronopifolia" means "having
leaves like the Mustard, Coronopus". The
plant was first collected by Edwin James in 1820 near the forks of the
Platte River and was described by Torrey and Gray in their 1840 Flora of
North America.
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Oenothera pallida
(Pale Evening Primrose) Onagraceae (Evening Primrose Family) Semi-desert, foothills. Shrublands, openings.
Spring, summer. Oenothera pallida is highly variable in its growth characteristics: it can be an annual or, more commonly, a perennial; its height is from eight to twenty-four inches; stems are red and fleshy but often are woody and flaky in older plants; stems commonly lean and arch; leaves are narrow but can be entire, toothed, or deeply cut; plants can be glabrous (smooth without hairs) or hairy. Plants often spread from roots and can be so abundant that an area is dotted with red stems in early spring and then with numerous, glorious white flowers. Petals have noticeable yellow/green patches at their base. John Lindley named this species from a specimen collected by David Douglas (of Douglas Fir fame) in the early 1800s in the "north-west of North America". (Douglas' words as quoted in Intermountain Flora.) "Pallida" is Latin for "pale". More Oenothera pallida photographs.
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Range map © John Kartesz,
County Color Key
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Range map for Oenothera albicaulis
Range map for Oenothera caespitosa
Range map for Oenothera coronopifolia
Range map for Oenothera pallida |
Species present in state and native
Species present in state and exotic
Species not present in state
Species present and not rare
Species present and rare
Species extirpated (historic)
Species extinct
Species noxious
Species exotic and present
Eradicated
Questionable presence
