Buffalo Bur (Solanum rostratum): Prickly Nightshade with Yellow Flowers

Buffalo Bur (Solanum rostratum): Prickly Nightshade with Yellow Flowers

A gardener photographed a thistle plant with "stickers" on stems and leaves, under a thistle bird feeder. They thought it might be a nyjer plant but only found yellow flowers. The plant grew 3-4 feet high, 2-3 inches wide, covered in flowers and pods.

Thistle Plant

Expert Identification

The plant is buffalo bur (Solanum rostratum), also called prickly nightshade or Kansas thistle—not a true thistle but a nightshade. Related to potatoes and tomatoes, but all parts are poisonous (and thorny). It's a noxious weed due to long thorns; some get painful dermatitis from pricks. It spreads Colorado potato beetle. In fall, the plant breaks off and rolls like tumbleweed, spreading seeds; pods break off and are painful to step on. It has pretty long-lasting yellow flowers. The expert recommended monitoring, picking up dropped pods with gloves, pulling the whole plant in fall (with gloves) after rain (taproot). Enjoy it in the meantime.