Showiest of all the Tick Trefoils, this plant is covered with bright purple pea-like flowers in the heat of mid-summer. A deep taproot makes this plant incredibly drought-resistant. A member of the Legume Family, it improves the soil by adding nitrogen, and the seeds are used by a variety of birds and other wildlife. Loves clay, and will grow on any moderately rich well-drained or slightly damp soil. Spreads by means of “stick-tight” seeds. Hardy to Zones 3 - 7.