Hoary Spine Aster
Family: Asteraceae (A Utah Flora – Compositae) – Sunflower Family
Biennial (winter annual) or short-lived perennial herbs from taproots; stems 3.2” to 2' (8 to 60 cm) tall or more
Leaves: alternate; simple; entire or pinnatifid to toothed or lobed; 0.4” to 4” (1 to 10 cm) long, 0.04” to 0.88” (1 to 22 mm) wide
Flowers: 15 to 25 pink to pink-purple or white rays, 0.2” to 0.48” (5 to 12 mm) long, 0.06” to 0.1” (1.5 to 2.5 mm) wide ; involucres 0.24” 0.48” (6 to 12 mm) high, 0.24” to 0.72” (6 to 18 mm) wide; flower head appears to be a single flower, but is composed of several flowers (a composite)
Pollinators: other genera in this family are pollinated by insects
Fruits: achene – 1 seeded with hard shell
Blooms in Arches National Park: late April, May, June, July, August, September, October, November
Habitat in Arches National Park: desert shrub and pinyon-juniper communities
Location seen: upper Courthouse wash, Windows road, outside Arches National Park in Bull Canyon (near Gemini Bridges)
Other: The genus name, “Machaeranthera”, means “sickle anther” and refers to the shape of the anthers. The species name, “canescens” means “gray hairs or grayish”.
This plant is an endemic.
This family is the most advanced and complex of the dicots. The family is rich in oils and resins and is found in every part of the world, but is infrequent in the tropical rainforest. Aquatic or semi-aquatic species are also uncommon.
Did You Know?
Landscape Arch is the longest arch in Arches National Park, measuring 306 feet from base to base. In 1991, a massive slab of rock fell from its underside, resulting in an even thinner ribbon of rock.