Common Name: Purple Milkweed

General Information

Asclepias purpurascens is an erect, herbaceous perennial plant producing a cluster of rather stout, unbranched stems 40 - 100cm 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[]. A very ornamental plant, it is sometimes grown in gardens.
The plant can self-seed freely if the seedpods are not removed prior to ripening and can also spread freely by rhizomes. It often forms extensive colonies in the wild[]. If intending to grow this species outside ts native range then the possibility of it escaping into the wild should be considered[].

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

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Range

Eastern N. America - South Dakota to Minnesota, south to Tennessee

Habitat

Dry to moist thickets, woods and openings[]. Thickets and open woods, prairies and fields, spreading to roadsides and railways[].

Properties

Weed Potential	Yes
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Perennial
Height	0.75 m
Pollinators	Bees, Insects, Lepidoptera
Self-fertile	Yes
Cultivation Status	Ornamental, Wild

Cultivation Details

Prefers a well-drained light rich or peaty soil and a sunny position[, , ]. Does well in poor, dryish soils[]. Established plants are drought tolerant[].
A very ornamental plant[], it is closely related to Asclepias syriaca, except its flowers are deep rose pink and its leaves are more pointed[, ].
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

This species is very similar to Asclepias syriaca and is likely to have been used in the same ways. These uses are as follows:-

Unopened flower buds - cooked. They taste somewhat like peas. They are used like broccoli[].
Flowers and young flower buds - cooked. They have a mucilaginous texture and a pleasant flavour, they can be used as a flavouring and a thickener in soups etc[, , ].
The flower clusters can be boiled down to make a sugary syrup[, ]. The flowers are harvested in the early morning with the dew still on them[]. When boiled up they make a brown sugar[].

Young shoots - cooked. An asparagus substitute[, , , , , , ]. They should be used when less than 20cm tall[]. A slightly bitter taste[].
Tips of older shoots are cooked like spinach[, ].
One recipe suggests you parboil the leaves or young shoots for three minutes, then discard the bitter water and replace with clean boiling water. (Cold water tends to fix the bitterness.) You can repeat this process p to three times to fully leach any bitterness (and many of the nutrients[]), then cook the leaves for 15 minutes before seasoning them. A pinch of soda can be added during cooking to break down the fibe and improve flavour[].

Young seed pods, 3 - 4 cm long, cooked[, , , ]. They are very appetizing. Best used when about 2 - 4cm long and before the seed floss forms, on older pods remove any seed floss before cooking them[, ]. If picked at the right time, the pods resemble okra[].

The sprouted seeds can be eaten[].

An edible oil is obtained from the seed[, ].

The latex in the stems is a suitable replacement for chicle and can be made into a chewing gum[, , ]. It is not really suitable for use in tyres[]. The latex is found mainly in the leaves and is destroyed by frost[]. Yields are higher on dry soils[].

Medicinal

The latex is used as a cure for warts[].

This species is very similar to Asclepias syriaca and is likely to have been used in the same ways. These uses are as follows:-

The root is anodyne, diaphoretic, diuretic, emetic, expectorant and purgative[, , ]. It has been used in the treatment of asthma, kidney stones, venereal disease etc[, ]. Caution is advised, see the notes above on toxicity.
An infusion of the pounded roots has been used by the women of some native North American Indian tribes to promote temporary sterility[, ].

The leaves and/or the latex are used in folk remedies for treating cancer and tumours[]. The milky latex from the stems and leaves is used in the treatment of warts[, , , ]. The latex needs to be applied at least daily over a period of up to a few weeks to be effective.

The stems can be cooked and applied as a poultice on rheumatic joints[].

One reported Mohawk antifertility concoction contained milkweed and jack-in-the-pulpit, both considered contraceptive. Dried and pulverized, a fistful of milkweed and three Arisaema rhizomes were infused in a pint of water for 20 minutes. The infusion was drunk, a cupful an hour, to induce temporary sterility[].

The rhizome is used in homeopathy as an antioedemic and emmenagogue in the treatment of dropsy and dysmenorrhoea[].

Other Uses

This species is very similar to Asclepias syriaca and is likely to have been used in the same ways. These uses are as follows:-

A good quality fibre is obtained from the inner bark of the stems. It is long and quite strong, but brittle[]. It can be used in making twine, cloth, paper etc[, , ]. The fibre is of poor quality in wet seasons[]. It is easily harvested in late autumn after the plant has died down by simply pulling the fibres off the dried stems[]. It is estimated that yields of 1,356 kilos per hectare could be obtained from wild plants[].

The seed floss is used to stuff pillows etc or is mixed with other fibres to make cloth[, , , ]. It is a Kapok substitute, used in Life Jackets or as a stuffing material[]. Very water repellent, it can yield up to 550 kilos per hectare[]. The floss absorbs oil whilst repelling water and so has also been used to mop up oil spills at sea. Candlewicks can be made from the seed floss[, ]. In cultivation, only 1 - 3% of the flowers produce mature pods[]. It is estimated that yields of 1,368 kilos per hectare could be obtained from wild plants[].

Rubber can be made from latex contained in the leaves and the stems[, , , ]. It is found mainly in the leaves and is destroyed by frost[]. Yields of 197 kilos per hectare can be expected from wild plants, it is estimated that by selection these yields could be increased to 897 kilos[]. Yields are higher on dry soils[]. The latex can also be used as a glue for fixing precious stones into necklaces, earrings etc[]. The latex contains 0.1 - 1.5% caoutchouc, 16 - 17% dry matter, and 1.23% ash. It also contains the digitalis-like mixture of a- and b-asclepiadin, the antitumor b-sitosterol, and a- and b-amyrin and its acetate, dextrose and wax[].

Pods contain an oil and a wax which are of potential importance.

The seed contains up to 20% of an edible semi-drying oil[, ]. It is also used in making liquid soap[].

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.