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Wyoming FFA Agronomy Contest


Poisonous Weeds

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Wyeth Lupine

wyeth lupine

Fabaceae (Pea family)

A perennial plant reproducing by seeds. Stems are upright and branched, often forming large showy clumps up to 18 inches in height. Flowers range from whit to purple on Wyeth lupine which are more open than those of other species. Leaflets and stems are covered with fine hair. Palmate leaves are composed of 6 to 8 leaflets radiating from a central point. Flowers mature from the bottom of the plant to the top forming hairy pods containing several round seeds. Hungry sheep are often poisoned by lupine plants when being trailed through ranges in late summer. Cows eating lupines during early pregnancy sometimes have calves with skeletal defects. Lupines contain poisonous alkaloids throughout the growing season and even though there are some species that are not poisonous, precautions should always be taken with livestock. Poisoning can occur in sheep ingesting less than 1/4 pound of the plants, while cattle must eat over 1 pound for poisoning to occur. Control of lupin with herbicides should be done before the bud stage of growth.