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Zigadenus (venenosus)

Dave Skinner
PMC Farm Manager
USDA NRCS - Pullman Plant Materials Center
Room 211A Hulbert Hall WSU
Pullman, Washington 99164-6211
509-335-2940 (fax)

Family Scientific Name: Liliaceae
Family Common Name: lily
Scientific Name: Zigadenus venenosus S. Watson gramineus (Rydb.) Walsh ex M. Peck
Common Synonym: Zygadenus venenosus
Common Name: death camas
Species Code: ZIVEG
Ecotype: Paradise Creek drainage near Pullman, Washington.
General Distribution: dry to mesic grasslands, shrub-steppe, lithosolic sites, and open forests of western North America from British Columbia south to Baja California and east to Saskatchewan and New Mexico. The Palouse phase is mostly var. gramineus.
Wetland indicator status is FACU (US Fish and Wildlife Service 1988).
Known Invasiveness: Generally not considered invasive. Because all parts of Z. venenosus are poisonous, and it increases with grazing, it is often considered a weed in range and pasture by livestock managers.
Propagation Goal: bulbs
Propagation Method: seed
ProductType: Container (plug)
Stock Type: 10 cu. in.
Time To Grow: 0
Propagule Collection: Fruit is a capsule. Seed is tan in color. It is collected when the capsules begin to split in August and is stored in paper bags or envelopes at room temperature until cleaned. Seed can be shaken into envelopes or bags, or the entire capsule can be removed from the stem. Where the plants are plentiful, the entire inflorescence can be collected by clipping it from the plant. All plant parts, including seeds and capsules, are poisonous and should be handled with diligence and care.
Propagule Processing: Seed shaken from capsules needs no cleaning. Capsules can be crushed to release seed. Seed is then cleaned with an air column separator. Clean seed is stored in controlled conditions at 40o Fahrenheit and 40% relative humidity.
Pre-Planting Treatments: For a western Washington ecotype, the highest germination occurred with 6 weeks of cold moist stratification and cool germination temperatures (Drake & Ewing, undated).
For this Palouse ecotype, extended cold, moist stratification is needed. Cool spring temperatures may also be necessary. In trials at the PMC, no germination occurred without stratification and no seed germinated after 30 days cold, moist stratification. Seed sown in late December and left outside did not germinate the first season, but germinated well after a second winter. Seed sown in containers outdoors in November will germinate the following spring. Seed can also be sown directly in the field in late fall in a firm, weed free seedbed. Seed should be lightly covered to a depth of no more than 1/8 inch.
Growing Area Preparation/
Annual Practices for Perennial Crops:
In late October or early November seed is sown in10 cu. in. Ray Leach Super cell conetainers filled with Sunshine #4 and covered lightly. A thin layer of coarse grit is applied to the top of the planting soil to prevent seeds from floating during watering. Conetainers are watered deeply and placed outside.
In late October, seed can be sown directly in the ground at a rate of 30-40 seeds/linear foot. Seedings should be made in a firm, weed-free seedbed. A firm seed bed holds moisture near the surface of the soil and assures accurate seed placement. Seed should be placed so that it is barely covered by soil.
Establishment Phase: Containers remain outside. They are watered only during dry spells. Germination will begin as daytime temperatures warm in March, and may occur over 2-4 weeks.
Length of Establishment Phase: 2-4 weeks
Active Growth Phase: Plants are watered as needed while outside and fertilized once a week with a water soluble, complete fertilizer. They are moved to the lath house in June.
Plants will not grow beyond the 1-2 true leaf stage the first season. They will often senesce in mid summer. Senescent plants are given only enough water to prevent the medium from drying completely.
Length of Active Growth Phase: 2-3 seasons
Hardening Phase: Since the plants are grown outside and are dormant in the autumn, additional hardening is not needed.
Harvesting, Storage and Shipping: Plants are stored in the lath house over winter. They should be afforded some protection from extreme cold temperatures. Mulch or foam sheets provide sufficient protection. The protection should be removed in late winter or early spring as temperatures begin to rise. Plants are kept in containers for 2 more seasons in the lath house.
In August or September of the third year, the containers are dumped out and the bulbs are separated from the soil using hand screens.
Other Comments: Plants may be propagated by division (Kruckeberg 1996). This method should only be used for plants growing in cultivation. Plants should not be dug up from stands in the wild.
Z. gramineus is a common synonym in older treatments.
When the genus was first described, it was spelled Zigadenus. Etymologically, Zygadenus would be the correct spelling and some later authors adopted this spelling. The original spelling has priority according to the rules of nomenclature (Flora of North America Editorial Committee, eds. 1993+).
References: Craighead, John J., Frank C. Craighead, and Ray J. Davis. 1963. A Field Guide to Rocky Mountain Wildflowers. Houghton Mifflin Co. Boston, MA. 277 pp.
Daubenmire, R.F. 1970. Steppe Vegetation of Washington. Washington State Univ. Coop. Ext. Service EB 1446. Pullman, WA.
Dayton, William A. 1960. Notes on Western Range Forbs: Equisetaceae through Fumariaceae. USDA, Forest Service Agricultural Handbook No. 161. 254 pp.
Drake, Deanne, and Kern Ewing. undated. Germination Requirements of 32 Native Washington Prairie Species. Center for Urban Horticulture, University of Washington, Seattle, WA. Available online at http://www.southsoundprairies.org/documents/completedgerminationdoc.pdf Accessed 3/11/08.
Faust, Ralph and Peggy. 1999. Wildflowers of the Inland Northwest. Museum of North Idaho. Coeur d'Alene, ID. 141 pp.
Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico. 7+ vols. New York and Oxford. Oxford University Press. Online at http://www.fna.org/FNA/
Hitchcock, C. Leo, and Arthur Cronquist. 1973. Flora of the Pacific Northwest. University of Washington Press. Seattle, WA. 730 pp.
Jolley, Russ. 1988. Wildflowers of the Columbia Gorge.Oregon Historical Society Press. Portland, OR. 332pp.
Kruckeberg, Arthur R. 1996. Gardening with Native Plants of the Pacific Northwest. 2nd ed. University of Washington Press. Seattle, WA. 282 pp.
Larrison, Earl J., Grace W. Patrick, William H. Baker, and James A. Yaich. 1974. Washington Wildflowers. The Seattle Audubon Society. Seattle, WA. 376 pp.
Lyons, C.P. 1956. Trees, Shrubs and Flowers to Know in Washington. J.M. Dent & Sons (Canada) Limited. Vancouver, BC. 211 pp.
Lyons, C.P. 1997. Wildflowers of Washington. Lone Pine Publishing, Renton, WA. 192 pp.
Parish, Roberta, Ray Coupe, and Dennis Lloyd (eds.). 1996. Plants of Southern Interior British Columbia. Lone Pine Publishing, Vancouver, BC, Canada. 463 pp.
Piper, C.V., and R.K. Beattie. 1914. The Flora of Southeastern Washington and Adjacent Idaho. Lancaster, PA. Press of the New Era Printing Company. 296 p.
Rickett, Harold W. 1973. Wildflowers of the United States: The Central Mountains and Plains. Vol. 6. (3 parts). McGraw Hill, New York.
St. John, Harold. 1963. Flora of Southeastern Washington and of Adjacent Idaho. 3rd edition. Outdoor Pictures. Escondido, CA. 583 pp.
Stubbendieck, James, Stephan L. Hatch, and Charles H. Butterfield. 1997. North American Range Plants. 5th edition. University of Nebraska Press, Lincoln, NE. 501 pp.
Taylor, Ronald J. 1992. Sagebrush Country. Mountain Press Publishing Co. Missoula, MT. 211 pp.
USDA ARS National Genetic Resources Program. Germplasm Resources Information Network - (GRIN) [Online Database]. National Germplasm Resources Laboratory, Beltsville, Maryland. URL: http://www.ars-grin.gov2/cgi-bin/npgs/html/taxon.pl?448068 (11 March 2008).
USDA, NRCS. 2008. The PLANTS Database (http://plants.usda.gov, 11 March 2008). National Plant Data Center, Baton Rouge, LA 70874-4490USA.
US Fish and Wildlife Service. 1988. National list of vascular plant species that occur in wetlands. US Fish & Wildlife Service Biological Report 88 (24).
Whitson, Tom D., Larry C. Burrill, Steven A. Dewey, David W. Cudney, B.E. Nelson, Richard D. Lee, and Robert Parker. 1996. Weeds of the West. 5th ed. Western Society of Weed Science. Newark, CA. 630 pp.


Skinner, David M,. 2008. Propagation protocol for production of Container (plug) Zigadenus venenosus S. Watson bulbs 10 cu. in.; USDA NRCS - Pullman Plant Materials Center Pullman, Washington. In: Native Plant Network. URL: http://NativePlantNetwork.org (accessed 2021/05/13). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.

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