Asclepias erosa (Desert milkweed)

Asclepias erosa Torr.

Desert milkweed

Kingdom	Plantae	Plants, but not fungi, lichens, or algae
Subkingdom	Tracheobionta	Vascular plants—plants with a “circulatory system” for delivering water and nutrients
Division	Magnoliophyta	Flowering plants, also known as angiosperms
Class	Magnoliopsida	Dicotyledons—plants with two initial seed leaves
Subclass	Asteridae	A large class that encompasses asters
Order	Gentianales	Gentians, coffee, gardenias, frangipani, many others
Family	Asclepiadaceae	Includes some herbs, twining shrubs, lianas, leafless stem succulents, rarely trees
Genus	Asclepias	For Asklepios, the Greek god of healing
Species	erosa	Jagged or bitten off at the edges, as if irregularly gnawed, referring to the ruffled, saw-edged leaf margins

About plant names...

Desert milkweed is native to northern Baja California, southern California, and Arizona. It favors dry slopes, roadsides, and washes, at elevations below 5000' (1.5 km), in full sun.

Plants: Single, erect, yellow-green stems, to 3½' (1 m) in height, rarely approaching 6½' (2 m).

Leaves: Leaves are a pale whitish green color, sometimes darker green, with prominent white veins. They are opposite, and vary from hairless to very hairy. Leaves are often curled, with wrinkled edges, and are lanceolate to ovate.

Flowers: Flowers are cream-colored to yellowish or greenish, forming roughly spherical umbels about 1½-3½" (3.8-8.9 cm) in diameter. Each flower has 5 petals, which open fully and may be bent back (reflexed). Fully opened, the flowers are about ⅜" (9.5 mm) around. The reproductive parts of the flower form a second star-shaped structure in the center. Flowers appear from April to July.

Fruits: Oval-shaped, sharp-tipped capsules, 2½-3½" (7-9 cm) long, containing seeds with long, silken parachutes.

Edibility: Milkweed stems contain a thick latex sap that some indigenous peoples roasted, producing a kind of chewing gum.

Online References:

Asclepias erosa on calscape.org

Asclepias erosa on www.americansouthwest.net

Asclepias erosa on CalPhotos

Asclepias erosa on arizonensis.org

Asclepias erosa at the Lady Bird Johnson Wildflower Center

Asclepias erosa on www.inaturalist.org

Asclepias erosa on Calflora

Asclepias erosa on SEINet—the Southwest Environmental Information Network