Silphium (genus)

Silphium is a genus of North American plants in the tribe Heliantheae within the family Asteraceae.
Members of the genus, commonly known as rosinweeds, are herbaceous perennial plants growing to to more than tall, with yellow flowerheads that resemble sunflowers. In the rosinweeds, the ray florets in the head are female and the disc florets are male; this differs from sunflowers, where ray florets are sterile and disc florets are perfect, capable of producing both pollen and seeds.
The name of the genus comes from the Ancient Greek word for a North African plant whose identity has been lost, though it is known its gum or juice was prized by the ancients as a medicine and a condiment.

Species

Species in the genus include:Silphium albiflorum A.Gray – white rosinweed – TXSilphium asteriscus L. – starry rosinweed – TX OK LA AR MO IL IN KY TN AL MS GA FL SC NC VA WV OH MD PA NYSilphium brachiatum Gatt. – Cumberland rosinweed – TN AL GASilphium compositum Michx. – kidneyleaf rosinweed – TN AL GA FL SC NC VA WVSilphium glutinosum J.R. Allison ALSilphium integrifolium Michx. – wholeleaf rosinweed – NM TX LA OK AR MO KS CO WY SD NE IA IL IN KY TN MS AL WI MI MA ONTSilphium laciniatum L. – compassplant – NM TX LA OK AR MO KS CO SD NE MN IA IL IN KY TN MS AL WI MI VA PA NY ONTSilphium laeve Hook. Silphium mohrii Small – Mohr's rosinweed – TN AL GASilphium perfoliatum L. – cup plant – NM TX LA OK AR MO KS CO SD ND NE MN IA IL IN KY TN MS AL WI MI NC VA DE PA NY NJ CT RI MA VT NH ME ONT QUE NBSilphium perplexum J.R.Allison – Old Cahaba rosinweed – ALSilphium pinnatifidum Elliott – Cutleaf prairie dock – AL GA KY TNSilphium radula Nutt. – roughstem rosinweed – KS MO AR OK TX LASilphium terebinthinaceum Jacq. – prairie rosinweed, prairie dock – IA MO AR MS AL GA SC NC VA WV TN KY OH IN IL WI MI NY ONTSilphium ternatum Sessé & Moc. – MexicoSilphium trifoliatum L. – whorled rosinweed – AL GA IN KY MD NC SC OH PA VA WVSilphium wasiotense M.Medley – Appalachian rosinweed – KY TN

Formerly included

Numerous species are now regarded as members of the genera Berlandiera and Verbesina.