The cobalt milkweed beetles from my last post were feeding on showy milkweed (Asclepias speciosa). Certain plants, orchids come to mind immediately, have reputations for being spectacularly beautiful. Yet so many other wildflowers are just as attractive and striking. I think the showy milkweed flower is lovely.
A native perennial that occurs in disturbed areas throughout the Western United States, showy milkweed can reproduce by seeds or underground rhizomes and often forms extensive colonies. When this wildflower out competes or displaces other vegetation because of its vigorous growth it is considered a noxious weed. Showy milkweed grows from one to four feet in height.
The oval to oblong leaves occur along the stem in opposite pairs and have prominent veins. The entire plant looks greyish green due to the soft fine hairs that cover the leaves and give them a velvety appearance.
The flowers, rose purple, creamy or pinkish when young, age to a yellowish color. The inflorescence (flower cluster) is an umbel (flower stalks arising from a single point like the spokes of an umbrella). Each flower has five reflexed (bent back) sepals, five stamens (pollen bearing organ) and two ovaries (female). The five petals are long, curving horns that protrude toward the center. I think each individual flower is lovely.
The flat showy milkweed seeds are reddish brown and borne in a pod. When fully matured each seed has a tuft of hairs that aid in wind dispersion.
All the foliage parts of showy milkweed exude a milky sap that contains toxic cardenolides, which can cause nausea and vomiting in low doses and death when consumed in quantity. The cobalt milkweed beetle has evolved a resistance to the showy milkweed toxins. Although showy milkweed is toxic to livestock, as long as there is sufficient forage available the animals will not eat showy milkweed. Therefore only under conditions of starvation is showy milkweed a threat to animals.
Hummingbirds, bees, butterflies and other insects are attracted to showy milkweed flowers for their sweet nectar and are important showy milkweed pollinators.
Showy milkweed leaves are edible only if prepared properly by boiling in several changes of water. I have never tried eating milkweed leaves. Besides having a natural aversion to anything labeled “toxic”, I do not believe the soggy mass resulting from prolonged boiling of the leaves makes the effort worthwhile. The flowers have a high sugar content and were cooked down by Native Americans to make a sweet syrup. Again, the general toxicity of milkweed has kept me from attempting to make milkweed flower syrup.
Showy milkweed sap has been used to treat warts and other skin conditions. The plant was also used to treat a variety of other ailments from kidney stones and asthma to cancer and venereal disease. Herbalists also consider showy milkweed an antiseptic.
Indigenous groups used the stems of showy milkweed as a coarse fiber or for cordage. Difficult as it is to imagine, the fluff from showy milkweed seeds was also spun into yarn and then woven into a special fabric used by Native American dancers in the Zuni, New Mexico area.
Showy butterfly weed, creek milkweed and Greek milkweed are other colloquial names for A. speciosa.
These showy milkweed plants were photographed along the canal in the McArthur Swamp (Shasta County CA).