Asclepias californica, (California milkweed)
A. californica is endemic to California but is most widespread in the southern part of the state. This is a drought tolerant species that does well in hot dry conditions. Like other drought tolerant milkweeds, the stems and leaves are covered with a thick covering of long hairs giving the plant a woolly appearance. This plant can be found growing on slopes in clay and sandy soils. If blossoming, the violet flowers contrast starkly with the woolly appearance of the foliage.
Flower: Umbels are pendulous. 10 +/- flowers per umbel. Color varies from a dull or bright pink to lavender. Wool like hair is everywhere, except on the flower head, but there is hair on the outside of the corolla lobe. No horns present. Corolla reflexes backward. Flower head is 1/3 – 1/2 in (8-10 mm) long.
Foliage: Thick stems and leaves are covered with dense hair. Stands erect to reclining. Leaf arrangement is opposite and attachment is sessile or has a short petiole. Mature plants have multiple stems.
Habitat: Flats, grassy slopes, and open woods.
Height: 36-48 in (91 ½ – 122 cm). Can grow in clumps up to 42 inches in width.
Leaves: Ovate, oblong to lanceolate. Approximately 2-7 in (5-18 cm) long and 1-3 in (2 ½ – 7 ½ cm) wide.
Blossoming Season: April – July.
Life span: NA
Propagation: By seed.
Pods: 3-4 in (7 ½ –10 cm) long by ¾ -1 ½ in (2- 2 ½ cm) wide. Pods are covered with short hair as well as short soft spikes. The spikes are 1/8-1/4 in (3-6 mm) long.
Seed Color: Brown.
Environment and Growth Requirements
Overhead Conditions: Not shade tolerant; requires full sun.
Precipitation: Very drought tolerant. Less than 8 in to 35 in (20-89 cm) annually.
Soil Texture: Sandy, clay, and rocky soils.
Temperature: Can tolerate a minimum temperature of 10 to 20 Fahrenheit (-12 to -6 Celsius).
Work Cited: laspilitas.com, Plants.usda.gov, californiagardens.com, wikipedia.org, calflora.org, Arborday.org, Eduplace.com, Books.google.com (An Illustrated Flora of the Pacific States Le Roy Abrams, Roxana Stinchfield Ferris)
Photos: Bobby Gendron & David S.