Practical
Plants

Asclepias rubra

Red Silkweed

No photo available

Taxonomy and growth

Life cycle
perennial
Height
1.2 m
Fertility
self fertile
Flower type
hermaphrodite
Pollinators
Bees, Insects, Lepidoptera

Uses

Toxicity

Toxicity warning. The historical record reports a hazard for this plant. Do not use it to decide which parts are safe to eat or use medicinally.

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[12]. They are usually avoided by grazing animals[12].

Edible uses

Flower buds - cooked as potherbs or added to soups[10]. Young shoots and leaves - cooked as potherbs or added to soups[10]. Young seed pods, 3 - 4 cm long, cooked[10]. Flower clusters can be boiled down to make a sugary syrup[10]. A chewing gum can be made from the latex contained in the stem and leaves, but it is possibly toxic[10].

Plant part
Flowers
Product or use
Gum
Plant part
Leaves
Plant part
Seedpod
Product or use
Sweetener

Medicinal uses

Historical medicinal uses. These records describe reported uses. They do not establish safety or effectiveness. Ask a qualified health professional before using any plant medicinally.

The latex is used as a cure for warts[6].

Product or use
Warts

Material uses

The following reports refer to other members of this genus and are possibly also appropriate for this species[K]. A good quality fibre is obtained from the bark, used in making twine, cloth, paper etc[16][3][7]. It is of poor quality in wet seasons[3]. It is easily harvested in late autumn after the plant has died down by simply pulling the fibres off the dried stems[7]. The seed floss is used to stuff pillows etc or is mixed with other fibres to make cloth[3][5][7][8]. It is a Kapok substitute, used in Life Jackets or as a stuffing material[3]. Very water repellent, it can yield up to 550 kilos per hectare[3]. The floss has also been used to mop up oil spills at sea. Candlewicks can be made from the seed floss[3][10]. Rubber can be made from latex contained in the leaves and the stems[13][14][2][5]. It is found mainly in the leaves and is destroyed by frost[3]. Yields are higher on dry soils[3]. Pods contain an oil and a wax which are of potential importance. The seed contains up to 20% of an edible semi-drying oil[15][3]. It is also used in making liquid soap[15].

Product or use
Fibre
Product or use
Latex
Product or use
Stuffing

Environment

Range
Eastern N. America - New Jersey and Pennsylvania to Florida, Missouri, Louisiana and Texas.
Habitat
Moist soils[11].
Light
full sun
Shade tolerance
light shade
Water
moderate
Hardiness
Zone 5+
Soil textures
sandy, loamy
Soil pH
acid, neutral, alkaline
Drainage
well drained
Tolerates Nutritionally Poor Soil
No
Drought
intolerant

Propagation

Seed - best sown in a greenhouse as soon as it is ripe in the autumn or in late winter[4][7]. We have also had good results from sowing the seed in the greenhouse in early spring[K], though stored seed might need 2 - 3 weeks cold stratification[4]. Germination usually takes place in 1 - 3 months at 18°c[4]. 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.

Cultivation

Prefers a well-drained light rich or peaty soil and a sunny position[1][4][9]. A very ornamental plant[1], it is closely related to A. lanceolata[9]. 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[K]. Plants resent root disturbance and are best planted into their final positions whilst small[4]. The flower of many members of this genus can trap insects between its anther cells, the struggles of the insect in escaping ensure the pollination of the plant[10].

References

  1. F. Chittendon. RHS Dictionary of Plants plus Supplement. 1956 Oxford University Press 1951-00-00

    ↩1↩2

  2. Kavasch. B. Native Harvests. Vintage Books 1979-00-00 ISBN 0-394-72811-4

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  3. Whiting. A. G. A Summary of the Literature on Milkweeds (Asclepias spp) and their utilization.

    ↩1↩2↩3↩4↩5↩6↩7↩8↩9

  4. Rice. G. (Editor) Growing from Seed. Volume 2. Thompson and Morgan. 1988-00-00

    ↩1↩2↩3↩4↩5

  5. McPherson. A. and S. Wild Food Plants of Indiana. Indiana University Press 1977-00-00 ISBN 0-253-28925-4

    ↩1↩2

  6. Grae. I. Nature's Colors - Dyes from Plants. MacMillan Publishing Co. New York. 1974-00-00 ISBN 0-02-544950-8

    ↩

  7. Buchanan. R. A Weavers Garden.

    ↩1↩2↩3↩4

  8. Hill. A. F. Economic Botany. The Maple Press 1952-00-00

    ↩

  9. Huxley. A. The New RHS Dictionary of Gardening. 1992. MacMillan Press 1992-00-00 ISBN 0-333-47494-5

    ↩1↩2

  10. Coffey. T. The History and Folklore of North American Wild Flowers. Facts on File. 1993-00-00 ISBN 0-8160-2624-6

    ↩1↩2↩3↩4↩5↩6↩7

  11. Britton. N. L. Brown. A. An Illustrated Flora of the Northern United States and Canada Dover Publications. New York. 1970-00-00 ISBN 0-486-22642-5

    ↩

  12. Diggs, Jnr. G.M.; Lipscomb. B. L. & O'Kennon. R. J Illustrated Flora of North Central Texas Botanical Research Institute, Texas. 1999-00-00 http://artemis.austincollege.edu/acad/bio/gdiggs/NCTXpdf.htm

    ↩1↩2

  13. Uphof. J. C. Th. Dictionary of Economic Plants. Weinheim 1959-00-00

    ↩

  14. Schery. R. W. Plants for Man.

    ↩

  15. Komarov. V. L. Flora of the USSR. Israel Program for Scientific Translation 1968-00-00

    ↩1↩2

  16. Saunders. C. F. Edible and Useful Wild Plants of the United States and Canada. Dover Publications 1976-00-00 ISBN 0-486-23310-3

    ↩

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