• Double O Arch

    Arches

    National Park Utah

Blazing Star (Blazing-star; Stickleaf)

Mentzelia sp.

Mentzelia sp.

Family: Loasaceae – Loasa Family

Mentzelia is the only genus of this family represented at Arches National Park. Many species in this genus are difficult to place with certainty because of the variability of plant size, leaf size, flower size and capsule size and shape.

Mentzelia albicaulis (Whitestem blazing star): Annual herbs; 3.9” to 1.3' (1 to 4 dm) tall; white or greenish-white stems

Mentzelia multiflora (Desert blazing star; Desert stickleaf): Perennial herbs from a taproot; 16” to 2.6' (4 to 8 dm) tall

Mentzelia pterosperma (Wingseed stickleaf): Perennial, biennial herbs, or flowering the first year; 2” to 1' (0.5 to 3 dm) tall; stems white with stiff coarse hairs

Mentzelia pumila ( Wyoming stickleaf): Biennial or short-lived perennial herbs from a stout taproot; whitish stems; 7.9” to 1.97' (2 to 6 dm) tall

Leaves: Mentzelia albicaulis: alternate; simple; lower leaves 1.2” to 5.9” (3 to 15 cm) long, entire, lobed or pinnatifid; upper leaves lance-shaped or linear, lobed or pinnatifid

Mentzelia multiflora: alternate; simple, can be lobed or toothed or pinnatifid; rough vegetation with rough, hooked, or even stinging hairs, hairy leaves; leaves are sticky, sand often sticks to their surfaces; lower leaves 1” to 4.8” (2.5 to 12 cm) long

Mentzelia pterosperma: alternate; simple; basal rosette leaves 1.2” to 2.9” (3 to 7.4 cm) long, 0.4” to 0.8” (10 to 20 mm) wide; leaves also along stems; hairy

Mentzelia pumila: alternate; simple; 3.3” to 7.9” (8.5 to 20 cm) long

Flowers: Mentzelia albicaulis: inflorescence with 1 to 3 flowers; 5 petals, 0.08” to 0.35” (2 to 9 mm) long; numerous stamens

Mentzelia multiflora: inflorescence with 1 to 3 flowers; 10 distinct yellow petals (the inner 5 somewhat shorter and narrower), petals 0.35” to 0.8” (9 to 20 mm) long, 0.24” to 0.32” (6 to 8 mm) wide, (described as 5 proper petals with 5 alternating petaloid staminodes in Intermountain Flora, Vascular Plants of the Intermountain West, U.S.A.); 4 to 5 sepals; numerous stamens which can be petaloid (can be as many as 200 stamens); 1 style

Mentzelia pterosperma: 10 yellow petals, 0.35” to 0.8” (9 to 20 mm) long, 0.16” to 0.3” (4 to 8 mm) wide, (described as 5 proper petals with 5 alternating petaloid staminodes in Intermountain Flora, Vascular Plants of the Intermountain West, U.S.A.); numerous stamens; outer stamens petaloid, 0.2” to 0.3” (5 to 8 mm) wide

Mentzelia pumila: inflorescence with 1 to 3 flowers; 10 yellow yellow or golden petals, often with a darker, orange to red-brown area at the base, 0.35” to 0.6” (9 to 15 mm) long, (described as 5 proper petals with 5 alternating petaloid staminodes in Intermountain Flora, Vascular Plants of the Intermountain West, U.S.A.); numerous stamens; outer stamens are petaloid, 0.6” to 0.8” (15 to 20 mm) long

Pollinators: some Mentzelia species are pollinated by bees

Fruits: capsule

Blooms in Arches National Park: April, May, June, July, August, September, October

Habitat in Arches National Park: desert shrub communities

Location seen: park road mile 0 to 2.5, park road mile 8, around Visitor Center buildings

Other: The genus name, “Mentzelia”, honors Christian Mentzel (1622-1701), a German botanist. The species name, “albicaulis”, means “white-stemmed”; the species name, “multiflora”, means “many flowers” referring to the quantity of flowers; the species name, “pterosperma”, means “having winged seeds”; and the species name, “pumila”, means “dwarf”.

Did You Know?

Common Raven

The common raven displays abilities to play and problem-solve that are rare among animals. This member of the crow family is also very vocal, communicating with over a dozen sounds. Perhaps because of these qualities, ravens have achieved a certain stature in both European and Native American folklore.