Cynoglossum
Cynoglossum is a genus of small-flowered plants in the family Boraginaceae. It includes 81 species native to Eurasia, Africa, New Guinea, and Australia.
Cynoglossum officinale, the common hound's-tongue, is a native of Asia, Africa, and Europe. It has been introduced into North America, and it is considered to be a troublesome weed because its burs stick to the wool of sheep and to other animals. Houndstongue is also toxic to cattle and other grazing animals due to the presence of pyrrolizidine alkaloids, which when ingested can lead to liver damage and photosensitivity in livestock.