Toxic: Toxic. Contains pyrrolizidine alkaloids. Toxic to humans, horses and cattle.
Growth Habit: biennial to short-lived taprooted perennial growing to 2 ½ feet in height
Leaves: Leaves are alternate, sessile; all leaves are entire, acute, linear lanceolate or linear-oblong with single midvein.
Stem: 1 meter in height, lateral stems often ascending, green with purple spotting (from spine bases), dense pubescent and also with straight spines. Spines clear and crystalline.
Flower: Corolla shallowly 5-lobed, zygomorphic, blue-purple to pink.
Roots: Large taproot.
Seeds: produces 500 to 2000 seeds per plant.
Reproduction: By Seed.
Habitat: Invades rangelands, pastures, roadsides, and idle areas particularly on coarse, sandy to gravelly soils.
Herbicides: Glyphosate, dicamba, 2,4 - D + dicamba, and Escort