Houndstongue (Cynoglossum officinale
) is a poisonous herb that is a member of the Borage family.
It is a biennial that produces a rosette the first year of growth and bolts and flowers during the summer of the second year. C. officinale
has a strong mousy-type smell, or of roasted peanuts. The flowers are small, arranged in clusters and not showy. C. officinale
prefers well drained, relatively sandy and gravelly soils. It can also be found in shady areas and especially under the canopy of forests and wetter grasslands.
contains four types of pyrrolizidine alkaloids---cynoglossine, consolidine, echinatine and heliosupine. Prolonged ingestion of pyrrolizidine alkaloids leads to liver damage and eventually liver failure. Substantial ingestion results in inhibition of neurons and paralysis. Most poisonings occur due to ingestion of C. officinale
in contaminated hay or feed. C. officinale
is more likely to contaminate hay at the time in which it is most toxic, when it is young and actively growing. The toxicity varies considerably, ranging from 15 to 360 mg/kg body weight per day of dried plant.