Montana Field Guide

Usually biennial. Stems branched, 40–100 cm. Leaves lanceolate, sessile above, 4–15 cm long, deeply serrate. Flowers white with pectinate bracts adherent to the hypanthium, nocturnal; sepals 2–4 cm long; petals lanceolate, apparently 10 (5 are staminodes), 3–6 cm long. Capsule broadly cylindric, 2–4 cm long; seeds flattened, narrowly winged, horizontal in 3 to 5 columns (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Sparsely vegetated, often gravelly soil of steep slopes, roadsides; plains, valleys (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

POLLINATION ECOLOGY
The showy, slightly fragrant white flowers of Ten-petal Blazingstar open roughly an hour before sunset and close again before morning. In an urban population within Helena, Montana, known flower visitors include the Hunt's Bumble Bee (Bombus huntii), White-bowed Smoothwing hoverfly (Scaeva affinis), and White-lined Sphinx moth (Hyles lineata) (Shane Sater, What's Going On Out There Blog).

More generally, the bumble bees Bombus centralis, Bombus fervidus, Bombus huntii, and Bombus pensylvanicus have been reported as pollinators of this plant species or its genus (Thorp et al. 1983, Williams et al. 2014).

INSECT TRAPPING
The foliage and floral bracts of Ten-petal Blazingstar are covered in stiff, barbed hairs that are capable of trapping soft-bodied invertebrates. In populations near Helena, Montana, preliminary observations indicate that these hairs have trapped and killed at least three species of flies and two species of moths. Meanwhile, certain other invertebrates, including spiders and weevils, are capable of navigating through the barbed hairs without getting stuck (Shane Sater, What's Going On Out There Blog).