Asclepias erosa, (Desert Milkweed)
A. erosa stands tall with white to yellow flowers in contrast to its green to yellow stem. Leaves vary from mostly smooth to highly pubescent, i.e. covered with fine cream-colored hair, making identification somewhat difficult. This species requires well-drained soils and is limited to deserts and near desert conditions with sandy soils.
Distribution: AZ, CA, NV, UT
Mexico: Baja California
Flower: Color is white to yellow. Horns protrude from the hoods. The corolla folds back from the hoods after blossoming. Umbels stand erect with 20 +/- flowers. Thick peduncle. Flower is 1/8 in (5-6 mm) long.
Foliage: Color is dull if leaves are covered with a fine cream-colored hair, but can also be glabrous. Stands erect. Yellow to green stems, thick at the base narrowing toward the top. Mature plants produce many stems with a width of up to 2 inches at the base. Leaf arrangement is opposite and attachment is sessile.
Habitat: Desert regions, mountain slopes, and roadsides.
Height: 18-47 in (50 – 120 cm).
Leaves: Ovate to laceolate. Color is pale to dark green. Can be hairy to hairless. Edges are wavy and bend upward around main central vein.
Toxicity: Low. Native American’s would boil the latex from this plant until hard and would use it as chewing gum.
Blossoming Season: May to July.
Life span: NA
Propagation: By seed.
Pods: Grows in autumn to late winter. Short, 2- 3 in (5-8 cm) long and ¾ -1 in (2-2.5 cm) thick.
Seed Color: NA
Environment and Growth Requirements
Overhead Conditions: Not shade tolerant, needs full sun.
Precipitation: Less than 8 in to 20 in (20-51 cm) annually.
Soil Texture: Needs dry granite, sand, or clay soils with low organic content.
Temperature: Survives in areas with minimum temperatures of -10 to 0 Fahrenheit (-23 to -18 Celsius).
Work Cited: fourdir.com, pfaf.org, Plants.usda.gov, laspilitas.com, mojavenp.org, Arborday.org, Eduplace.com, An Illustrated Flora of the Pacific States: Geraniaceae to Scrophulariaceae Le Roy Abrams, Roxana Stinchfield Ferris
Photos: Bobby Gendron