Western minniebush
General poisoning notes:
Western minniebush (Menziesia ferruginea) is a native shrub found in western Canada. This plant has occasionally been implicated in cases of sheep poisoning. Feeding experiments have shown that it does cause poisoning in sheep. It is considered less toxic that some other members of the heath family, such as Kalmiaspp. and Rhododendron spp. (Marsh 1914, Kingsbury 1964).
Description:
Shrubserect, branching, often forming thickets, 1-2.5 m, malodorous when bruised, bark of older branches loosely shredding or glabrous, young twigs finely hairy or somewhat glandular-pilose. Leaves: petiole 2-4 mm; blade light green abaxially, oblong-elliptic to obovate or ovate-elliptic to elliptic-obovate, 3-6 cm, base cuneate, margins glandular-ciliate, apex acute or rounded with mucronate tip ca. 0.1-0.2 mm, tapering to petiole, abaxial surface stipitate-glandular and/or hairy, midvein scales lanceolate-glandular, not cleft or, rarely, 2-cleft, adaxial surface pilose and/or sparsely stipitate-glandular. Pedicelsspreading to drooping, spreading to erect in fruit, filiform, 1-3 cm, stipitate-glandular with ± minute pilose hairs. Flowers appearing with leaves; calyx lobes broadly triangular, 0.5-1 mm, margins lacerate-ciliate, apex rounded to subacute, stipitate-glandular; corolla greenish or yellowish tinged with red or bronze, 6-10 × 5 mm, lobes 1.5 mm; nectariferous disc obscurely 8-crenate; filaments subulate, flattish, slightly dilated proximally, hairy near base; anthers linear; ovary globose, glandular but not hairy. Capsulesovoid to ovoid-oblong, 5-8 mm, glabrous or very sparsely stipitate-glandular and/or puberulent. Seeds pale brown, linear, 2.5-3 mm including 2 appendages 1 mm each. 2n = 26.
Menziesia ferruginea Sm.
Nomenclature:
Scientific Name: Menziesia ferruginea Sm.
Vernacular name(s): western minniebush
Other name(s): Fool’s huckleberry, mock or false azalea, rusty-leaf or rusty or Pacific or smooth menziesia Fool’s huckleberry, mock or false azalea, rusty-leaf or rusty or Pacific or smooth menziesia
Scientific family name: Ericaceae
Vernacular family name: heath
Geographic Information
Alberta, British Columbia.
Toxic parts:
Leaves.
Notes on Toxic plant chemicals:
Andromedotoxins (grayanotoxins) are diterpenoid alkaloids. These toxins are common to all poisonous members of the heath family (including Kalmia spp. and Rhododendronspp.).
Toxic plant chemicals:
Andromedotoxins.
Andromedotoxins
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.
Sheep
General symptoms of poisoning:
breathing, labored
gait, staggering
mouth, frothing of
nausea
paralysis
salivation
weakness.
