Silphium asteriscus

Silphium asteriscus, commonly called starry rosinweed,^[2] is an herbaceous plant in the family Asteraceae. It is native to the eastern United States, from Oklahoma and Texas east to Florida and Pennsylvania.^[3] It is a widespread species found in a variety of open habitats, such as prairies and woodlands.^[4]

Silphium asteriscus
Silphium asteriscus var. asteriscus
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Asterids
Order:	Asterales
Family:	Asteraceae
Genus:	Silphium
Species:	S. asteriscus
Binomial name
Silphium asteriscus L.[1]

Taxonomy

Additional research is needed to better understand the taxonomy of this species. It remains perhaps the most poorly-understood Silphium in eastern North America.^[5] It appears to show a high level of local variability throughout its range, which has been interpreted as either a species complex, a single highly variable species, or some combination of both. Due to conflicting information about the best circumscription of the varieties, the taxonomy of this species remains unsettled.^[6][7]

The most recent treatment from 2020 ranked Silphium asperrimum, Silphium dentatum and Silphium simpsonii at species status.^[7] If adopted, this leaves S. asteriscus with three remaining varieties. They are:

• Silphium asteriscus var. asteriscus - Appalachian and eastward; with a congested, hispid inflorescence
• Silphium asteriscus var. laitoflium - south and west of the Appalachians; with broad, opposite leaves and a spreading glabrous inflorescence
• Silphium asteriscus var. trifoliatum - widespread; similar to the above but with narrow whorled leaves^[7]

• 
  Line drawing of Silphium asteriscus