Also known as buffalo-bur, spiny nightshade, Colorado bur, Kansas thistle, bad woman, Mexican thistle, and Texas thistle, this annual is native to the Great Plains and a member of Solanaceae family, that also includes tomato, eggplant, and pepper. The plant grows 1-5′ tall from a branched taproot and has branched stems covered with sharp yellow prickles with purplish bases. The 6″ long leaves have deep, irregularly rounded lobes, toothless margins, and hairy surfaces. The main veins of the leaves are lined on both sides with long, sharply pointed yellow prickles. From early summer to mid fall, racemes of bright yellow flowers appear opening from the bottom up. The racemes are up to 6″ long and are composed of flowers that are about 1″ across and have 5 fused petals with crinkled edges. The fruit is a many seeded berry with a spiny covering. The plant is an annual and after seed set dies, breaks off at the base and becomes a tumbleweed, spreading its seeds as it is blown about. Buffalo bur nightshade is considered an undesirable plant because of its spines and poisonous characteristic,s and is classified as a noxious and invasive weed in many areas. The derivation of the genus name, Solanum, is not clear. It may come from the Latin word sol, meaning sun, referring to the possible resemblance of the flowers of some in the genus to the sun. A second possible origin is the Latin word solare, meaning to soothe, referring to the possible psychoactive properties of some of the species. The specific epithet, rostratum, is the Latin word meaning beaked, hooked, or curved.
Type: Annual
Bloom: Racemes of yellow, 5 petaled flowers early spring to mid fall
Size: 1-5′ H
Light: Full sun
Soil: Average, medium moist to dry, well-drained; tolerates alkaline conditions.
Hardiness: Not relevant
Care: Remove plants before seed set to avoid spread
Pests and Diseases: None of significance but susceptible to damage by aphids and several beetles including Colorado potato beetle
Propagation: Seed
Companion Plants: Not relevant
Outstanding Selections: None
Photo Credit: Wikipedia