Crocanthemum canadense (L.) Britton
Family: Cistaceae
common rock-rose, long-branch frostweed
Crocanthemum canadense image
Robert W. Freckmann  
Etymology: Helianthemum: from the Greek helios, "sun," and anthemon, "flower," because the flowers open only in the sun
Plants: erect, perennial, 8"-24" tall forb; stems scattered, branching when mature, the branches becoming taller than the main stem
Leaves: alternate, narrowly-oblong, tapering at the base and tip
Flowers: yellow, 5-parted, 2/3"-1 1/8" wide; inflorescence of 1-2 flowers in a branched cluster (cyme) at the top of the stem; blooms May-June, usually 2-3 weeks earlier than H. bicknellii.
Habitat: dry; prairies, woods, inland sands
Conservation Status: Native