White camas
General poisoning notes:
White camas (Zigadenus
elegans) is a native perennial herb that grows from a bulb. The plant can
be found across most of Canada from British Columbia to New Brunswick and in
parts of northwestern Canada. The plant contains several steroidal alkaloids,
including zygacine, which can poison livestock and humans. White camas has
caused poisoning in sheep and may have been involved in poisoning cattle.
Ingesting the bulbs can also cause poisoning. This plant is considered to be
about seven times less toxic that death camas (Zigadenus venenosus).
Poisoning is most common in early spring because this plant often is available
before other forage is plentiful (Kingsbury 1964, Panter and James 1989).
Description:
Plants 2–8 dm,
from bulbs; bulbs not clumped, tunicate, narrowly ovoid, 1.5–3 × 1–2 cm. Stems
without persistent leaf bases. Leaves: proximal blades 10–30 cm × 3–15 mm.
Inflorescences loosely racemose to paniculate, 10–50-flowered, with 1–4
branches, 0.9–2.5 dm × 3–6 cm. Flowers: perianth perigynous, rotate to
rotate-campanulate, 15–20 mm diam.; tepals persistent in fruit, cream colored
to greenish, ovate, 7–12 × 4–5 mm, somewhat narrowed at base; gland 1,
obcordate; pedicel erect at anthesis, 1–2.3 cm, bracts often tinged with purple
or pink, ovate, 5–20 mm. Capsules narrowly conic, 10–20 mm. 2n = 32.
Nomenclature:
Scientific Name: Zigadenus elegans Pursh
Vernacular
name(s): white camas
Other name(s): Mountain
death camas; zigadène élégant
Scientific family
name: Liliaceae
Vernacular family
name: lily
Geographic Information:
Alberta, British Columbia,
Manitoba, New Brunswick, Northwest Territories, Ontario, Quebec, Saskatchewan.
Notes on Poisonous plant parts:
All parts of the
plant are toxic. The early leaves are the most common cause of poisoning
because the plants grow early, before other forage is plentiful. The bulbs may
be pulled up and ingested if the ground is wet (Cheeke and Schull 1985, Panter
and James 1989).
Toxic parts:
All parts, bulbs, flowers,
leaves.
Notes on Toxic plant chemicals:
A steroidal
alkaloid, zygacine, is one of several alkaloids contained in death camas. The
lethal dose is estimated at between 2.0-6.0% of animal body weight. This plant
is considered to be less toxic than death camas, Zigadenus venenosus
(Kingsbury 1964).
Toxic plant chemicals:
Zygacine.
Chemical
diagram(s) are courtesy of Ruth McDiarmid, Biochemistry Technician, Kamloops
Range Station, Agriculture and Agri-Food Canada, Kamploops, British Columbia,
Canada.
Animals/Human Poisoning:
Note: When an
animal is listed without additional information, the literature (as of 1993)
contained no detailed explanation.
Cattle
Horses
Humans
General symptoms of
poisoning:
Blood
pressure, low, coma, dizziness, heart rate, slow.
Notes on poisoning:
Ingesting the
bulbs, mistaken for onions, can cause poisoning in humans, even though this
species is considered less toxic than death camas (Zigadenus venenosus).
Sheep
General symptoms of
poisoning:
Ataxia,
breathing, rapid, coma, death, death, mouth, frothing of, nasal discharge,
nausea, salivation, urination, frequent, vomiting.
Notes on poisoning:
Symptoms of
poisoning are similar for all species of animals. Symptoms in sheep include
excessive salivation, froth around the nose and mouth, nausea, vomiting,
muscular weakness, ataxia, possible coma, and death. The heart fails before
respiration. Postmortem findings reveal the heart in complete diastole. Lesions
include severe pulmonary congestion, hemorrhage, and edema. One-time loss of
sheep has been reported as 500 head in some species of Zigadenus (Cheeke
and Schull 1985, Panter and James 1989).
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