Purple Prairie Clover

Petalostemum purpureum

D.Y. 2nd Ed., pg. 
Height: 1 - 2 ft. tall
Stem: Erect, slender, & wiry.
Inflorescens: At the top of the stem; tiny purple flowers are crowded into a cylindrical spike; and each of the tiny flowers has 5 protruding, bright orange yellow anthers (on the stamens). 
Leaves: Alternate, 3-5 leaflets, - very small and narrow.
Roots: The taproot is short & vertical, with many branches. The wide-ranging system helps the plant to absorb water.