Hypochaeris radicata
Image: Walter Siegmund
Description
The leaves, which may grow up to eight inches (20 cm) tall, are lobed and covered in fine hairs, forming a low-lying rosette around a central taproot. Forked stems carry bright yellow flower heads, and when mature these form seeds attached to windborne "parachutes". All parts of the plant exude a milky sap when cut.Hypochaeris species are used as food plants by the larvae of some Lepidoptera species including the shark moth.
Propagation instructions - seeds
Hand removal and cultivation can control both species. Common catsear is more difficult, as it has a taproot which can resprout. If the entire taproot can be removed, as with a shovel, to several inches below the root crown, common catsear will not grow back.
Mowing is not effective in controlling catsear.
Light to moderate grazing usually facilitates survival of these species.
Burning can stimulate germination of common catsear and probably smooth catsear seed.
No known biocontrol agents are available for either species of Hypochaeris
(DiTomaso, J.M., G.B. Kyser et al. 2013. Weed Control in Natural Areas in the Western United States. Weed Research and Information Center, University of California. 544 pp.)