buffalobur, buffalobur nightshade, buffalobur, Colorado bur, horned nightshade, Kansas thistle, Mexican thistle, Texas thistle
- Solanum rostratum is an annual herbaceous plant that can grow up to 2 ft. (0.6 m) tall.
- Stems and leaves have extremely sharp spines, so take care when handling. Leaves are alternate, bright green, petiolate, 4-5 in. (10.2-12.7 cm) long, and pinnately lobed.
- Flowers have five petals and are yellow, and 1 in. (2.5 cm) across. Calyx tube is 1 in. (2.5 cm) long, and spiny. Flowering occurs from May to October.
- Fruits are dry berries up to 0.4 in. (1 cm) in diameter covered in sharp spines and contain several wrinkled, flat, black seeds.
- Ecological Threat
- S. rostratum prefers moist soils and areas like pastures, waste ground, and roadsides. Although it is native to most of North America, it is considered a noxious weed in some states.
- King County Department of Natural Resources and Parks Water and Land Resources Division
- Oregon Department of Agriculture Plant Programs, Noxious Weed Control
- Washington State Noxious Weed Control Board
- University of California, Jepson Flora Project
- Virginia Tech Weed Identification Guide
- USDA NRCS PLANTS
- USDA ARS GRIN
Images from Bugwood.org