Yellow iris
General poisoning notes:
Yellow iris (Iris pseudacorus) is a naturalized plant found in wet areas in parts of southern Canada. This plant has poisoned cattle and swine and may cause similar symptoms in humans if the rhizomes are ingested. The plant juices can cause dermatitis in sensitive humans. In British Columbia cattle were poisoned by a cultivated blue-flowered Iris species. The symptoms of that poisoning are described under this species (Bruce 1920, Cooper and Johnson 1984).
Description:
Rhizomes pink, freely branching, producing extensive clumps, 2–3 cm diam., with fibrous remains of old leaves; roots fleshy. Stems usually 1-branched, solid, 7–15 dm. Leaves: basal deciduous, at first erect, then recurved, blade dark green, with prominent median thickening, 4–10 dm × 2–3 cm, slightly glaucous basally; cauline equaling inflorescence unit. Inflorescence units 4–12-flowered; spathes green with brown margins, outer spathe strongly keeled, inner without keel, 6–9 cm, subequal, margins not scarious. Flowers: perianth bright yellow; floral tube 0.6–0.8 cm, with no constriction into ovary; sepals bright yellow or cream colored, lanceolate to ovate or suborbiculate, 5–7.5 × 3–4 cm, base abruptly attenuate, claw ca. 1/2 length of limb, signal a darker yellow basal patch limited by short, brown lines; petals without veining, lanceolate to spatulate, 2–3 cm; ovary triangular in cross section with concave sides and narrow groove at each angle, 1.5 cm; style keeled, 3–4 cm, crests spreading, 1–1.2 cm, laciniate at apex; stigmas rounded with prominent tongue; pedicel 2.5–7 cm. Capsules prismatic to oblong-ovoid, obscurely 3-angled with obvious groove at each angle, 3.5–6 cm, beak 5 mm. Seeds D-shaped, flattened, 6–7 mm, corky, lustrous. 2n = 34.
Iris pseudacorus L.
Nomenclature:
Scientific Name: Iris pseudacorus L.
Vernacular name(s): yellow iris, pale-yellow iris, yellow flag, yellow water iris, fleur-de-lis, iris jaune
Scientific family name: Iridaceae
Vernacular family name: iris
Geographic Information:
British Columbia, Manitoba, Nova Scotia, Prince Edward Island, Ontario, Quebec.
Notes on Poisonous plant parts:
Ingesting the rhizome causes poisoning in animals, and the plant juices cause dermatitis in sensitive individuals (Cooper and Johnson 1984).
Toxic parts:
Plant juices, rhizome
Notes on Toxic plant chemicals:
The toxin in Iris species has not been confirmed, but a glycoside, iridin (or irisin), has been implicated (Cooper and Johnson 1984).
Toxic plant chemicals:
Iridin.
Iridin
Animals/Human Poisoning:
Note: When an animal is listed without additional information, the literature (as of 1993) contained no detailed explanation.
Cattle
General symptoms of poisoning:
Abdominal pains, blistering, diarrhea, death, mouth, irritation of, salivation, recumbency.
Notes on poisoning:
Ingesting yellow flag rhizome has apparently caused diarrhea and bloody feces in cattle in Europe. The toxin can survive drying because yellow flag in hay causes diarrhea (Cooper and Johnson 1984).
In a case in British Columbia, cattle ingested rhizomes from an unidentified blue-flowered cultivated Iris species. Three calves showed symptoms and died within 4 days. Initial symptoms included recumbency and excessive salivation. The glands of the head and throat became hard and enlarged. Raised sores appeared on the lips and muzzle, becoming yellowish scabs that irritated animals. Acute abdominal pain occurred, and bloody feces were passed. Death followed. Postmortem findings showed irritation of the lower stomachs and intestines. The kidneys, liver, and spleen were very dark-colored. Unfortunately, the identity of this iris was never determined (Bruce 1920). Livestock should be denied access to any Iris species that grow in the wild or in gardens, because ingestion may cause poisoning.
Humans
General symptoms of poisoning:
Blistering.
Swine
General symptoms of poisoning:
Abortion, diarrhea, death.
Notes on poisoning:
Swine that ingest rhizomes suffer diarrhea; one sow hemorrhaged, aborted, and died (Cooper and Johnson 1984).
