Tufted Evening Primrose
Oenothera cespitosa Nutt.
Family: Onagraceae, Evening Primrose
Genus: Oenothera
Synonyms: Oenothera caespitosa
Other names: moon-rose
Nomenclature: cespitosa = tufted
Nativity / Invasiveness: Montana native plant
Medicinal plant
No edibility data

General: tufted, stemless to short-stemmed perennial rarely as much as 25 cm tall, hairless to densely short-hairy or long-soft-hairy, depending on variety.

Leaves: basal, narrowly to broadly oblanceolate, usually 10-25 cm long and 1-2.5 cm broad, oblanceolate, gradually tapered to the slender stalks which are about equal to the shallowly pinnatifid to shallowly toothed blades.

Flowers: single on each stalk from the base of the plant, open in the evening. The free hypanthium slender, somewhat flared above, 5-12 cm long, greenish or reddish. The 4 calyx lobes 2.5-3.5 cm long, joined or free, often sharply bent back. The 4 petals white, aging to pinkish, cordate, 2.5-4.5 cm. long, slightly notched. Anthers 8-13 mm long. Style 2-4 cm long, the 4 stigma lobes 5-8 mm long. May-July.

Fruits: capsules, woody, oblong-ovoid, 1-2 cm long, 4-angled but not winged, often covered with warty bumps, stalkless or with a stalk as much as 1 cm. long. Seeds numerous, not hair-tufted.


Talus slopes, roadcuts, and dry hills, in most parts of MT. Also widespread over much of w. U.S.
Medicinal Uses

Tufted evening primrose was used medicinally by several Indian tribes, among those the Blackfoot, the Gosiute, the Isleta, Navajo, Kayenta and Hopi Indians. A wet poultice of crushed or pounded roots was applied to sores and swellings, especially to inflamed sores. A poultice of dried, ground leaves was used on sores for rapid healing. It was also applied for prolapses of the uterus. The plant was used with Kachina ears for sore eyes. It was also used as a toothache medicine.

Sub taxa:

Our specimen belong to ssp. cespitosa Nutt.

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