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
Kenneth J. Sytsma