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Asparagaceae FAMILY Least Concern

Yucca constricta

Yucca constricta

Edibility
2/5
Medicinal
0/5

Safety & Hazards

The roots contain saponins[1]. Although poisonous, saponins also have a range of medicinal applications and many saponin-rich plants are used in herbalism (particularly as emetics, expectorants and febrifuges) or as sources of raw materials for the pharmaceutical industry. Saponins are also found in a number of common foods, such as many beans. Saponins have a quite bitter flavour and are in general poorly absorbed by the human body, so most pass through without harm. They can be removed by carefully leaching in running water. Thorough cooking, and perhaps changing the cooking water once, will also normally remove most of them. However, it is not advisable to eat large quantities of raw foods that contain saponins. Saponins are much more toxic to many cold-blooded creatures, such as fish, and hunting tribes have traditionally put large quantities of them in streams, lakes etc in order to stupefy or kill the fish and make them easy to catch[PFAF].

Cultivation Details

HabitEvergreen Shrub
Growth—

Yucca constricta is a plant of semi-arid regions in southern N. America and, although capable of tolerating occasional short-lived temperatures down to around -5°c, does not grow very well in moist climates, being especially intolerant of winter wet[2]. Thrives in any soil but prefers a sandy loam and full exposure to the south[3, 2]. Plants are hardier when grown on poor sandy soils[2]. Established plants are very drought resistant[2]. Yuccas are pollinated by small, white Yucca moths (Tegeticula yucasella and related species) with which they have a special plant-insect mutualism. At night, the fragrant flowers attract the female moth that feeds on the nectar. She then rolls pollen from the flowers into a ball that is three times the size of her head and carries the pollen ball to the next flower. There, she first lays eggs inside the immature ovary and then deposits the pollen on the flower’s stigma ensuring that seeds will form to feed her progeny. Because the larvae mature before they are able to consume all of the seeds (60 to 80% of the seeds remain viable), the plants are able to reproduce as well[4]. In regions where the moth cannot live and, if fruit and seed are required, then hand pollination is necessary[2]. This can be quite easily and successfully done using something like a small paint brush. Individual crowns are monocarpic, dying after flowering[5]. However, the crown will usually produce a number of sideshoots before it dies and these will grow on to flower in later years[5]. Members of this genus seem to be immune to the predations of rabbits[5]

Propagation

Seed - sow spring in a greenhouse. Pre-soaking the seed for 24 hours in warm water may reduce the germination time. It usually germinates within 1 - 12 months if kept at a temperature of 20°c. Prick out the seedlings into individual pots when they are large enough to handle and grow them on in the greenhouse or cold frame for at least their first two winters. Plant them out into their permanent positions in early summer and consider giving them some winter protection for at least their first winter outdoors - a simple pane of glass is usually sufficient[PFAF]. Seed is not produced in Britain unless the flowers are hand pollinated. Root cuttings in late winter or early spring. Lift in mid spring and remove small buds from base of stem and rhizomes. Dip in dry wood ashes to stop any bleeding and plant in a sandy soil in pots in a greenhouse until established[6]. Cite as: Temperate Plants Database, Ken Fern. temperate.theferns.info. 2026-02-21. <temperate.theferns.info/plant/Yucca+constricta>

Pollinators

Hand

References

  1. [1]A Field Guide to Medicinal Plants. Eastern and Central N. America. — Foster. S. & Duke. J. A. · Houghton Mifflin Co. · 1990 · ISBN 0395467225 ↩︎A concise book dealing with almost 500 species. A line drawing of each plant is included plus colour photographs of about 100 species. Very good as a field guide, it only gives brief details about the plants medicinal properties.
  2. [2]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.
  3. [3]Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement. — Bean. W. · Murray · 1981 · ISBN - ↩︎A classic with a wealth of information on the plants, but poor on pictures.
  4. [4]Plants Database — United States Department of Agriculture · http://plants.usda.gov/java/factSheet ↩︎An online database with an excellent collection of fact sheets about native N. American plants.
  5. [5]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.
  6. [6]Propagation of Trees, Shrubs and Conifers. — Sheat. W. G. · MacMillan and Co · 1948 · ISBN - ↩︎A bit dated but a good book on propagation techniques with specific details for a wide range of plants.
  7. [7]Flora of N. America — http://flora.huh.harvard.edu/fna/ ↩︎An on-line version of the flora with an excellent description of the plant including a brief mention of plant uses.
  8. [8]IUCN Red List of Threatened Species — http://www.iucnredlist.org/ ↩︎A list of plants under threat and facing possible extinction, usually with brief details of the threats and information on habitat.
  9. [9]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.
  10. [10]Growing from Seed. Volume 4. — Bird. R. (Editor) · Thompson and Morgan. · 1990 · ISBN - ↩︎Very readable magazine with lots of information on propagation. A good article on Yuccas, one on Sagebrush (Artemesia spp) and another on Chaerophyllum bulbosum.
  11. [11]Yucca — 2007 · http://www.naturaldatabase.com/ ↩︎A very comprehensive database of herbs, minerals and other natural products taken to promote health
  12. [12]Yuccas of the Southwest — Webber J.M. · USDA · 1953 ↩︎Rather dated, but very detailed information on the various species and their uses
  13. [13]Manual of the Trees of N. America. — Sargent. C. S. · Dover Publications Inc. New York. · 1965 · http://www.biodiversitylibrary.org/ · ISBN 0-486-20278-X ↩︎Two volumes, a comprehensive listing of N. American trees though a bit out of date now. Good details on habitats, some details on plant uses. Not really for the casual reader. It can be downloaded from the internet.
  14. [14]A Weavers Garden — Buchanan. R. · McGraw-Hill Contemporary · 1987 · ISBN 0934026289 ↩︎Covers all aspects of growing your own clothes, from fibre plants to dyes.
  15. [PFAF]Plants for a Future — pfaf.org ↩︎