Family: Cistaceae
Bicknell's rock-rose, hoary frostweed, rock-rose
[Helianthemum bicknellii Fernald]
Marcie O'Connor
Merel R. Black
University of Wisconsin - Madison (WIS-VP)
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 clustered, branching when mature, the branches not becoming taller than the main stem
Leaves: wedge or triangular-shaped
Flowers: yellow, 5-parted, 2/3"-1" wide; inflorescence of 2-10 stalked flowers in a branched cluster (cyme) at the top of the stem; blooms June-July usually 2-3 weeks later than H. canadense
Habitat: dry; prairies, woods, inland sands; in sandy soil
Conservation Status: Native
Plants: erect, perennial, 8"-24" tall forb; stems clustered, branching when mature, the branches not becoming taller than the main stem
Leaves: wedge or triangular-shaped
Flowers: yellow, 5-parted, 2/3"-1" wide; inflorescence of 2-10 stalked flowers in a branched cluster (cyme) at the top of the stem; blooms June-July usually 2-3 weeks later than H. canadense
Habitat: dry; prairies, woods, inland sands; in sandy soil
Conservation Status: Native
Dry sandy prairies, dry-mesic prairies, sand barrens, pine barrens, oak savannas, cedar glades, open woods of oak-pine, sandy lakeshores and riverbanks, sandstone and quartzite rock outcrops, fields, and along roadsides and railroads. This species tends to produce more cleistogamous flowers than C. canadense, and late-season plants have upper stems with very dense clusters of fruits.
Floristic Rating: Coefficient of Conservatism = 6 Atlas of the Wisconsin Prairie and Savanna Flora: by T.S. Cochrane & H.H. Iltis: habitat, distribution infomation / flowering and fruiting times USDA Plants Database: Federal Distribution and detailed information including photos
Merel R. Black
Merel R. Black
Aaron_Carlson
