perennial sowthistle, field sowthistle, creeping sowthistle, field sow-thistle
- Sonchus arvensis is a perennial herbaceous plant. Stems can reach 4.9 ft. (1.5 m) in height and contain milky sap.
- Leaves are sessile, alternate, clasping, up to 12 in. (30.5 cm) long and decrease in size further up the stem, margins undulate with sharp spines.
- Flowering occurs in June to October, when yellow, tight, dandelion-like flower heads develop at the tips of the branches. Flowers open 2-3 hours after sunrise and close about noon.
- Fruits are reddish, ribbed and have a tuft of hair at the top.
- Ecological Threat
- Sonchus arvensis occurs along roadsides, railroads and other disturbed habitat. It is native to Eurasia.
- McWilliams, Jack 2004. Sonchus arvensis, Fire Effects Information System, U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory
- Minnesota Department of Natural Resources
- University of California, Jepson Flora Project
- Flora of North America, www.eFloras.org
- USDA NRCS PLANTS
- USDA ARS GRIN
Images from Bugwood.org