South Dakota Native Plant Research
Loasaceae : Mentzelia decapetala

Loasaceae : Mentzelia decapetala


Download Seed: Flat seeds of tenpetal blazingstar are whitish and 4-5 mm long. (59 KB)

Download Seedling: Seedling of ten petal mentzelia two months after germinating in research greenhous eat SDSU. (87 KB)

Download Vegetative:Leaf of ten petal mentzelia in early September growing near SDSU. (54 KB)

Download Fruitling: Ten petal mentzelia after fruiting late in the fall. (650 KB)

Download Preflower: Ten petal mentzelia before its flower opens. (274 KB)

Download Mature plant in the Black Hills (1.1 MB)

Download Mature Plant in University gardens (849 KB)

Family Name


Common Name

Ten-petal blazingstar, Ten-petal mentzelia

Native American Name

Lakota: čhaŋȟlóǧaŋ maȟ’áwaŋglakela


Mentzelia decapetala is a coarse, erect, shrubby looking, biennial to weakly perennial herb growing up to 1 m tall. There are 1 to several stems that branched above, and the lower stems develop a whitish, exfoliating bark. The leaves are alternate, fleshy, lanceolate, 4-15 cm long, 1.5-4 cm wide, pinnatifid with wavy lobes, the lower leaves petiolate and the upper sessile. The flowers are solitary or in small clusters at the ends of branches. The 5 sepals are 1-5 cm long with pointed tips, and the 10 petals are white to cream colored, 5-7 cm long and 1-2 cm wide, oblanceolate to spatulate and often overlapping. There are numerous stamens that are shorter than the petals and form a yellow center in the opened flower. When open, the petals create a showy display, each flower up to 15 in diameter. The flowers open in late afternoon and close around midnight. The fruit is a cylindrical capsule 3-5 cm long and 1,5-2 cm wide with numerous, flattened, minutely winged seeds. Ten-petal blazingstar blooms from July into September along roadsides, and other disturbed places, including the Missouri River drainage, scattered throughout South Dakota.

Additional Notes

Ten-petal blazingstar adds a very different look and feel to a native plant garden. The foliage is coarse and dramatic in appearance and the flowers are eye-catching, opening in the late afternoon and best viewed around sunset. They are easy to grow in well drained, poorer soils. They do not do well in rich soils. The flowers attract bumblebees, flies and moths. In the right locations they will reseed themselves.

Horticulture Notes

Seed Collection: Collect seed in September-October when pods are brown
Germination: Fall or spring sowing as the seeds have little dormancy.
Soils: Clay or silt well drained soils
Light: Full sun
Water: Dry to moist as long as the soils dry out between watering.

Loasaceae : Mentzelia decapetala