Melanthiaceae – Death Camas

Melanthiaceae

“Don’t eat white camas” is a common saying around the Willamette Valley. Referring not to a true member of the genus Camassia, but to a perennial monocot with similar bulbs found in another family all together. Above ground structures are easily identified as Toxicoscordion venenosum (formerly Zigadenus venenosus), also known as Death Camas. Both Camassia and Toxicoscordion occur in the same habitat types, however only one of these species’ bulbs contain lethal toxins. Therefore, before Native Peoples could safely conduct seasonal bulb harvests throughout Western Oregon and Washington wetland prairies, it was incredibly important to remove Toxicoscordion venenosum in the Spring before flowers senesced and blooms could be differentiated.

Native to the Northern Hemisphere, Melanthiaceae is a family of perennial monocot herbs known for their showy sepals and petals. Because of their three-merous corollas, many within this group were once classified into the Liliaceae, but their taxonomy was reordered by the APG III system of 2009. Melanthiaceae includes 17 genera divided into five tribes, including a number of spring flowers found throughout the Cascades including trilliums and bear grass (Xerophyllum tenax).

Toxicoscordion venenosum (Formerly Zigadenus venenosus)

Growth Habit

Showy perennial monocot with many white flowers arising from a 12 to 25 mm diameter bulb.

Leaves

Basal, grass-like, and channeled with parallel veins. Grow up to 30 cm long, tapering up the stem and are somewhat rough to the touch.

Stems

range in height from 15 to 70 centimeters and are smooth, lacking any hairs.

Flowers

Inflorescence is a raceme of many flowers in a compact, terminal cluster. Foul smelling, creamy to yellowish white blossoms are bell shaped, with six petals and green glands at the base.

Fruits

Flowers produce cylindrical, papery capsules that are 8 to 14 mm wide.

Ecology

(In the Arid Western US) FACU, Facultative Upland species, can grow in a variety of environments from seasonally wet prairies to rocky cliffs, and forests below 2,600 meter above sea level.

Notes

 The bulb and leaves of this plant are extremely poisonous to humans and grazing animals. Consuming as little as just 2 to 6% of one’s body weight can be fatal. Death Camas contains a chemical known as zygacine and other esters that are neurotoxins, interrupting normal neural activity. Unfortunately, bulbs have been confused with those of the edible C. quamashC. leichtlinii, or alliums occurring in the same ecosystems, killing those who ingest them.

United States Department of Agriculture, Natural Resources Conservation Service. Ethnobotany, Culture and Use of Great Camas. Portland, OR September 1999 Plant Materials Technical Note NO. 23

http://www.nrcs.usda.gov/Internet/FSE_PLANTMATERIALS/publications/orpmctn230999.pdf

Angiosperm Phylogeny Group (2009). A revision of the Angiosperm Phylogeny Group’s classification regarding the orders and families of flowering plants: APG III. Botanical Journal of the Linnean Society. 161 (2): 105–121. doi:10.1111/j.1095-8339.2009.00996.x. Retrieved 2013-06-26.

Guard, J. (1995). Wetland Plants of Oregon and Washington. Lone Pine Publishing, Edmonton, Alberta.

Jepson eFlora: Toxicoscordion venenosa http://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=93851

Canadian Poisonous Plants Information System – Zigadenus venenosus http://www.cbif.gc.ca/eng/species-bank/canadian-poisonous-plants-information-system/all-plants-common-name/death-camas/?id=1370403267102&gt

Guard, J. (1995). Wetland Plants of Oregon and Washington. Lone Pine Publishing, Edmonton, Alberta. 99.

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