Solanum rostratum is an annual herbaceous plant that can grow up to 2 ft. (0.6 m) tall.
Foliage
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
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.
Fruit
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.