Astragalus desperatus var. desperatus
Family: Fabaceae (A Utah Flora – Leguminosae) – Pea Family
Perennial herbs; 0.4” to 1' (1 to 30 cm) tall
Leaves: alternate; compound; 7 to 17 leaflets 0.08” to 0.52” (2 to 13 mm) long, 0.04” to 0.2” (1 to 5 mm) wide; leaves 0.4” to 4.8” (1 to 12 cm) long
Flowers: 5 pink or purple petals (a banner, 2 wings and 2 keels); keel shorter than the wings; 5 toothed sepals; bisexual; 5-10 stamens, 1 pistil; flowers 0.24” to 0.36” (6 to 9 mm) wide
Pollinators: other Astragalus species are pollinated by bees, moths and butterflies
Blooms in Arches National Park: January, February, March, April, May, June
Habitat in Arches National Park: desert shrub and pinyon-juniper communities
Location seen: park road mile 0 to 2.5, Delicate Arch trail, outside Arches National Park in Negro Bill Canyon
Other: The genus name, “Astragalus”, is the Greek name for “legume”, and may be derived from “astragalos” which means “ankle bone” referring to the shape of the leaves or the pods. The species name, “desperatus”, is one of the more humorous scientific plant names. It was named in 1891 by Marcus Jones who was “desperate” to find a name not already taken in the Astragalus genus (information about the species name from Al Schneider, www.swcoloradowildflowers.com).
This plant is endemic to Emery, Garfield, Grand (type specimen was collected near Cisco), Kane, San Juan and Wayne Counties in Utah and adjacent areas in Colorado and northern Arizona.
This family is ranked second to grasses in importance to people because species can fix nitrogen. However, some species, e.g., locoweeds and milkvetches, are poisonous due to selenium abstracted from the soil.
Did You Know?
There are over 2,000 cataloged arches in Arches National Park. In order to be considered an arch, an opening must measure at least three feet (in any direction).