Taxa: Silphium asteriscus, Silphium asteriscus var. asteriscus (Silphium asteriscus var. scabrum, Silphium dentatum var. gatesii), Silphium asteriscus var. dentatum (Silphium asteriscus var. angustatum, Silphium asteriscus var. laevicaule, Silphium asteriscus var. dentata, Silphium dentatum var. angustatu
... (show all)m, Silphium asteriscus ssp. dentatum), Silphium asteriscus var. latifolium (Silphium asteriscus var. latrifolium, Silphium trifoliatum var. latifolium, Silphium asteriscus ssp. latifolium), Silphium asteriscus var. simpsonii, Silphium asteriscus var. trifoliatum (Silphium trifoliatum var. trifoliatum, Silphium asteriscus ssp. trifoliatum)