Smooth-stemmed Eveningstar
Mentzelia laevicaulis (Dougl. ex Hook.) T & G.
Family: Loasaceae, Eveningstar
Genus: Mentzelia
Other names: smoothstem blazingstar
Nomenclature: laevicaulis = smooth stalk
Nativity / Invasiveness: Montana native plant
Medicinal plant
No edibility data

General: biennial or short-lived perennial from a deep taproot, 30-100 cm tall. Stem usually one and branched, rough with short, barbed, spine-like hairs throughout or nearly smooth near the base.

Leaves: alternate, the lower ones oblanceolate, deeply pinnatifid with wavy lobes, up to 15 cm long, the upper ones stalkless, oblong to ovate-oblong, less deeply lobed.

Flowers: terminal on numerous branch ends and often in the top 1 or 2 leaf axils, open at daytime, not fragrant, each with 1 to several linear, entire to few-toothed bracts at the base. Calyx 1-2.5 cm long at flowering, enlarging as the fruit matures, the 5 lobes linear, 1.5-4 cm long. The 5 petals lemon yellow, 2.5-8 cm long, narrowly oblong or oblong-lanceolate. Stamens very numerous, about 2/3 the length of the petals, the 5 outer ones often lacking anthers, expanded, but much narrower than the petals with which they alternate. Style usually slightly longer than the stamens, the stigma 3-4 mm long, angled. July-September.

Fruits: capsules, 1.5-3.5 cm long. Seeds numerous, borne horizontally, light grayish-green or brownish, flattened and distinctly winged.


Dry, open sites, up to the lower mountains, in most parts of MT. Also from B.C. and e. WA, s. to CA, UT and WY.
Medicinal Uses

Smooth-stemmed eveningstar was used medicinally by several Indian tribes, among those the Gosiute, Cheyenne, Mendocino and Montana Indians. The roots were used for earaches, rheumatism and arthritis, and were chewed for thirst prevention. An infusion of roots was taken for mumps, measles and smallpox, they were also used for fevers and complicated illnesses. Externally, infusions of roots were used for bruise swellings. A decoction of leaves was taken for stomachaches or used as a wash for skin diseases.

Sub taxa:

Our specimen belong to var. laevicaulis Dougl. T. & G., which has petals usually at least 4 cm long and fruit capsules more than 2 cm long.

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