
Asclepias speciosa
Asclepias speciosa
Safety & 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[1, 2]. The plants are usually avoided by grazing animals[1].
Cultivation Details
Prefers a well-drained light rich or peaty soil and a sunny position[3, 4, 5]. Grows well in poor, dryish, gravelly soils[6]. Established plants are drought tolerant[6]. A very ornamental plant[3], it is closely related to Asclepias purpurascens[5]. The roots can spread quite freely when the plant is in a suitable position[7]. 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[PFAF]. 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 (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[8, 9].
Propagation
Seed - best sown in a greenhouse as soon as it is ripe in the autumn or in late winter[4, 10]. We have also had good results from sowing the seed in the greenhouse in early spring[PFAF], 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..This species produces deep taproots which makes transplanting very difficult[6]. Trying to divide it will probably be equally difficult[PFAF]. 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. Cite as: Temperate Plants Database, Ken Fern. temperate.theferns.info. 2026-02-20. <temperate.theferns.info/plant/Asclepias+speciosa>
Pollinators
Bees, Insects, Lepidoptera
References
- [1]Illustrated Flora of North Central Texas — Diggs, Jnr. G.M.; Lipscomb. B. L. & O'Kennon. R. J · Botanical Research Institute, Texas. · 1999 · http://artemis.austincollege.edu/acad/bio/gdiggs/NCTXpdf.htm · ISBN 1-889878-01-4 ↩︎An excellent flora, which is also available on-line.
- [2]Poisonous Plants of North Carolina — http://www.ces.ncsu.edu/depts/hort/consumer/poison/poison.htm ↩︎An excellent concise but comprehensive guide to toxic plants that grow in N. Carolina. It lists even those plants that are of very low toxicity, including several well-known food plants such as carrots and potatoes.
- [3]RHS Dictionary of Plants plus Supplement. 1956 — F. Chittendon. · Oxford University Press · 1951 · ISBN - ↩︎Comprehensive listing of species and how to grow them. Somewhat outdated, it has been replaced in 1992 by a new dictionary (see [ 200 ]).
- [4]Growing from Seed. Volume 2. — Rice. G. (Editor) · Thompson and Morgan. · 1988 · ISBN - ↩︎Very readable magazine with lots of information on propagation. An interesting article on Ensete ventricosum.
- [5]The New RHS Dictionary of Gardening. 1992. — Huxley. A. · MacMillan Press · 1992 · ISBN 0-333-47494-5 ↩︎Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
- [6]KemperCentreForHomeGardeningPlantFinder — Missouri Botanical Garden · http://www.mobot.org/gardeninghelp/plantfinder/ ↩︎Basic cultivation details, plant uses, habitat etc for several thousand species of plants, mainly from the temperate zone.
- [7]Perennial Garden Plants — Thomas. G. S. · J. M. Dent & Sons, London. · 1990 · ISBN 0 460 86048 8 ↩︎A concise guide to a wide range of perennials. Lots of cultivation guides, very little on plant uses.
- [8]The History and Folklore of North American Wild Flowers. — Coffey. T. · Facts on File. · 1993 · ISBN 0-8160-2624-6 ↩︎A nice read, lots of information on plant uses.
- [9]Annals of the Missouri Botanical Garden Vol. 41 — Missouri Botanical Garden; St. Louis. · 1954 · http://www.biodiversitylibrary.org ↩︎A botanical publication, it contains an article on the genus Tachigali. It can be downloaded from the Internet.
- [10]A Weavers Garden — Buchanan. R. · McGraw-Hill Contemporary · 1987 · ISBN 0934026289 ↩︎Covers all aspects of growing your own clothes, from fibre plants to dyes.
- [11]The National Non-Food Crops Centre Crop Database — http://www.nnfcc.co.uk/crops/pd.cfm ↩︎An excellent on-line information source, with information on over 100 species (as of 2006) of plants being investigated as bio-crops.
- [12]Vascular Plants of the Pacific Northwest. — Hitchcock. C. L. · University of Washington Press · 1955 · ISBN - ↩︎A standard flora for Western N. America with lots of information on habitat etc. Five large volumes, it is not for the casual reader.
- [13]A Dictionary of Plants Used by Man. — Usher. G. · Constable · 1974 · ISBN 0094579202 ↩︎Forget the sexist title, this is one of the best books on the subject. Lists a very extensive range of useful plants from around the world with very brief details of the uses. Not for the casual reader.
- [14]Early Uses of Californian Plants. — Balls. E. K. · University of California Press · 1975 · ISBN 0-520-00072-2 ↩︎A nice readable book.
- [15]Edible Native Plants of the Rocky Mountains. — Harrington. H. D. · University of New Mexico Press · 1967 · ISBN 0-8623-0343-9 ↩︎A superb book. Very readable, it gives the results of the authors experiments with native edible plants.
- [16]Native American Ethnobotany — Moerman. D. · Timber Press. Oregon. · 1998 · ISBN 0-88192-453-9 ↩︎Very comprehensive but terse guide to the native uses of plants. Excellent bibliography, fully referenced to each plant, giving a pathway to further information. Not for the casual reader.
- [17]Dictionary of Economic Plants. — Uphof. J. C. Th. · Weinheim · 1959 · ISBN - ↩︎An excellent and very comprehensive guide but it only gives very short descriptions of the uses without any details of how to utilize the plants. Not for the casual reader.
- [18]A Field Guide to N. American Edible Wild Plants. — Elias. T. and Dykeman. P. · Van Nostrand Reinhold · 1982 · ISBN 0442222009 ↩︎Very readable.
- [19]Edible and Useful Wild Plants of the United States and Canada. — Saunders. C. F. · Dover Publications · 1976 · ISBN 0-486-23310-3 ↩︎Useful wild plants of America. A pocket guide.
- [20]Cornucopia - A Source Book of Edible Plants. — Facciola. S. · Kampong Publications · 1990 · ISBN 0-9628087-0-9 ↩︎Excellent. Contains a very wide range of conventional and unconventional food plants (including tropical) and where they can be obtained (mainly N. American nurseries but also research institutes and a lot of other nurseries from around the world.
- [21]Food Plants of the N. American Indians. — Yanovsky. E. · U.S. Depf of Agriculture. · ISBN - ↩︎A comprehensive but very terse guide. Not for the casual reader.
- [22]Nature's Colors - Dyes from Plants. — Grae. I. · MacMillan Publishing Co. New York. · 1974 · ISBN 0-02-544950-8 ↩︎A very good and readable book on dyeing.
- [23]Plants in British Columbian Indian Technology. — Turner. N. J. · British Columbia Provincial Museum · 1979 · ISBN 0-7718-8117-7 ↩︎Excellent and readable guide.
- [24]Plant Fibres for Papermaking. — Bell. L. A. · Liliaceae Press · 1988 · ISBN - ↩︎A good practical section on how to make paper on a small scale plus details of about 75 species (quite a few of them tropical) that can be used.
- [25]Plants for Man. — Schery. R. W. ↩︎Fairly readable but not very comprehensive. Deals with plants from around the world.
- [26]A Summary of the Literature on Milkweeds (Asclepias spp) and their utilization. — Whiting. A. G. · USDA; Washington · 1943 ↩︎A technical paper covering the many uses of the genus Asclepias.
- [PFAF]Plants for a Future — pfaf.org ↩︎