Native to the Midwestern prairies as well as the scrublands of the Southeast, these tough, pest-free, underappreciated perennials feature tall spikes of showy, sunflower-like blooms in mid- to late summer. Broken stems exude a gummy sap that smells like pine or turpentinehence the common name rosinweed. Erect stalks holding loose, branching clusters of blooms rise from a clump of large basal leaves; stalk leaves are smaller. In most species, the foliage is rough and hairy. Plants tolerate wet or dry conditions, grow particularly well in heavy soil. Easily started from seed or grown from young transplants. Good additions to wildflower meadows, naturalized areas, and (if staked) the back of the border. Resist deer.
S. dentatum. STARRY ROSINWEED. To 6 ft. tall, 23 ft. wide. Dark green, shallowly toothed leaves reach 1 ft. long. Star-shaped light yellow flowers with greenish yellow centers reach 4 in. across.
S. laciniatum. COMPASS PLANT. Common name refers to the basal leaves' tendency to orient themselves on a north-south axis. Foliage is green with pink veins; deeply cut basal leaves reach 112 ft. long, form a clump 2 ft. across. Blossom stalks rise 69 ft. high, carrying showy yellow flowers up to 5 in. across.
S. perfoliatum. CUP PLANT. Paired basal leaves are fused at the squarish stems, forming a cup that catches water; birds and butterflies will stop by for a sip. Dark green, nearly hairless, coarsely toothed leaves reach 14 in. long, may be triangular or pointed-oval; plant grows about 3 ft. wide. Stalks rising 48 ft. bear bright yellow, daisylike flowers up to 3 in. wide. Grows naturally in moist soils; provide regular water.
S. terebinthinaceum. PRAIRIE DOCK. Light green, spade-shaped basal leaves with coarsely toothed edges can reach 2 ft. long. Almost leafless flower stalks range from 310 ft. tall, may be red or green; blossoms are bright yellow, 23 in. wide. Plants reach 46 ft. wide. Once the stout taproot is established, prairie dock tolerates considerable drought.