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a.k.a. Black Snakeroot, Poison Onion, White Camas, Alkali grass, Poison sego, Crow Poison, Sandcorn Zigadenus (or Zygadenus ) venenosus
A perennial lily with a single bulb, with 5-6 basal, thickened, V-creased leaves, and snowy cream-colored flowers in a dense, terminal cluster. The underground bulbs are scaly. The plant emerges in early spring. Usually 30-60 cm (1-2 ft) high, growing from a bulb which resembles a small onion, but lacks any onion odor.
Entire plant, especially the onion-like bulbs, are highly toxic and is quite fatal to humans who mistake it for wild onions or Blue Camas. Entire plant is extremely toxic to grazing livestock. Respiratory problems occur after eating 1/2 to 2 pounds of the plant or 0.6 to 6.0% of body weight. The plant is toxic at all stages of growth. The flower cluster does not have to appear for the plant to be toxic.
Human and animal symptoms of Death Camas may appear from 1-8 hours after eating the plant. Recovery usually occurs within 24 hours. Symptoms include: excessive watering (foaming) of the mouth, burning following by numbness of the lips and mouth, thirst, headache, dizziness, nausea, stomach pain, persistent vomiting, diarrhea, muscular weakness, confusion, slow and irregular heartbeat, low blood pressure, subnormal body temperature. In extreme cases will result in difficulty in breathing, convulsions and coma followed by death.
No know antidote, treat symptomatically. Induce vomiting, or perform gastric lavage; follow with activated charcoal and saline cathertic; general supportive treatment for symptoms; maintain fluid and electrolyte balance; monitor breathing and heart rate, blood pressure; subcutaneous application of atropine, repeated as needed, will alleviate slow heart rate; for persistent low blood pressure, ephedrine or dopamine may be given; control convulsions with i.v. diazepam.
Dispose of the entire plant including the entire bulb. Take care you do not disturb the flower cluster, as it will distribute the seeds for next year's growth. Spraying in early spring is also a suggested in controlling the plant.
Field Guide to Plants Poisonous to LivestockWestern U.S.; Shirley A. Weathers; ISBN: 0-9660397-3-4, Rosebud Press; 1998
Common Posionous Plants and Mushrooms of North America; Nancy J. Turner, Ph.D. and Adam F. Szczawinski, Ph.D.; ISBN: 0-88192-312-5; Timber Press, Inc.; 1991
Weeds of Colorado; Robert L. Zimdahl, Cooperative Extension Colorado State UniversityFort Collins, CO 80523 Bulletin 521A; 1990
Weeds of the West; The Western Society of Weed Science / University of Wyoming ; Printer:Pioneer of Jackson Hole
ISBN: 0-941570-13-4; 1992 (revised)