Common Name: Desert Milkweed

General Information

Asclepias erosa is an erect, herbaceous perennial plant that is more or less woody at the base; it produces a cluster of very stout, unbranched or lightly-branched stems 100 - 200cm tall[].
Like most, if not all Asclepias species, the plants are likely to have been utilized for foods and other materials by the native North American tribes. See Asclepias syriaca for some idea of these potential uses[].

Known Hazards

Although no specific reports have been seen for this species, many, if not all, members of this genus contain toxic resinoids, alkaloids and cardiac glycosides. They are only toxic if eaten in large quantities, causing vomiting, stupor, weakness and spasma[, ].
The plants are usually avoided by grazing animals[].

Botanical References

,

Range

South-western N. America - California, Nevada, Utah, Arizona, Baja California

Habitat

Dry slopes and washes; at elevations below 1,500 metres in California[]. Gulches, washes, and canyons, Mohave and Colorado deserts[].

Properties

Edibility Rating
Other Uses Rating
Habit	Perennial
Height	0.75 m
Pollinators	Bees, Insects, Lepidoptera
Cultivation Status	Wild

Cultivation Details

Asclepias erosa is a plant of dry Mediterranean climates with hot summers and cool or even cold winters and most precipitation falling in the cooler months. Outside of this type of climate, the plant will require a well-drained soil and hot summers, with some protection in cold winters, if it is to thive. This protection can often be applied as a mulch, though it would need to be removed before new growth begins in the spring otherwise slug damage is very likely to occur[].
Prefers a well-drained light rich or peaty soil[, ]. Succeeds in poor soils.
Many members of this genus seem to be particularly prone to damage by slugs. The young growth in spring is especially vulnerable, but older growth is also attacked and even well-established plants have been destroyed in wet years[].
Plants resent root disturbance and are best planted into their final positions whilst small[].
The flower of many members of this genus can trap insects between its anther cells - the struggles of the insect in escaping (especially bees and wasps) pulls with it the pollinium (sacs of pollen) which are then transported to the next flower and deposited there, ensuring pollination of the flower[, ].

Edible Uses

The milky sap can be left to solidify, then heated over a fire to be used as a chewing gum[].

Medicinal

None known

Other Uses

Rubber can be made from latex contained in the stems and leaves[].

Propagation

Seed - best sown in a greenhouse as soon as it is ripe in the autumn or in late winter[, ]. We have also had good results from sowing the seed in the greenhouse in early spring[], though stored seed might need 2 - 3 weeks cold stratification[]. Germination usually takes place in 1 - 3 months at 18°c[]. As soon as the seedlings are large enough to handle, prick them out into individual pots and grow them on in the greenhouse for their first winter. Plant out when they are in active growth in late spring or early summer and give them some protection from slugs until they are growing away strongly.
Division in spring. With great care since the plant resents root disturbance. Pot the divisions up and place them in a lightly shaded position in the greenhouse until they are growing away strongly, then plant them out in the summer, giving them some protection from slugs until they are established..
Basal cuttings in late spring. Use shoots about 10cm long with as much of their white underground stem as possible. Pot them up individually and place them in a lightly shaded position in a greenhouse until they are rooting and growing actively. If the plants grow sufficiently, they can be put into their permanent positions in the summer, otherwise keep them in the greenhouse until the following spring and when they are in active growth plant them out into their permanent positions. Give them some protection from slugs until they are established.