Silphium terebinthinaceum var. terebinthinaceum  
Family: Asteraceae
basal-leaved rosinweed, prairie rosinweed, prairie-dock
[Silphium rumicifolium Small]
Silphium terebinthinaceum var. terebinthinaceum image
Christopher Noll  
Etymology: Silphium: old Greek generic name referring to resinous juice
Plants: erect, perennial, 2'-10' tall forb; stems mostly leafless and smooth
Leaves: all large, basal, long stalked, rough, un-lobed but toothed, with a wide, heart-shaped base
Flowers: head 2"- 3 1/2" wide with about 13-21 yellow rays 3/4"-1" long, disk 1/2"- 1 1/2" wide; inflorescence of several to many heads in an open, branched cluster; blooms July-Sept.
Habitat: full sun; moderate moisture to wet; prairies; in sandy, loamy soil
Conservation Status: Native
Silphium terebinthinaceum var. terebinthinaceum image
Kenneth J. Sytsma  
Silphium terebinthinaceum var. terebinthinaceum image
Janice Stiefel  
Silphium terebinthinaceum var. terebinthinaceum image
Paul Drobot  
Silphium terebinthinaceum var. terebinthinaceum image
Robert Bierman