Silphium asteriscus

{{Short description|Species of flowering plant}}

{{Use dmy dates|date=April 2020}}

{{Speciesbox

| image = Silphium asteriscus.jpg

| image_caption = Silphium asteriscus var. asteriscus

| genus = Silphium

| species = asteriscus

| authority = L.{{Cite web| url = http://botany.si.edu/ing/INGsearch.cfm?searchword=Silphium| title = Silphium| accessdate = 2008-06-24| date = 1996-02-09| work = Index Nominum Genericorum| publisher = International Association for Plant Taxonomy}}

}}

Silphium asteriscus, commonly called starry rosinweed,{{PLANTS|id=RHPE4|taxon=Silphium asteriscus|accessdate=18 January 2017}} 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.{{BONAP|ref|genus=Silphium|species=asteriscus|accessdate=18 January 2017}} It is a widespread species found in a variety of open habitats, such as prairies and woodlands.[http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=220012555 Flora of North America]

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.{{cite book |last=Chester |first=Edward |date=2015 |title=Guide to the Vascular Plants of Tennessee}} 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.[http://www.tropicos.org/Name/2726684?projectid=23 Flora of Missouri]{{cite web |url=http://www.herbarium.unc.edu/flora.htm |title= Flora of the Southern and Mid-Atlantic States}}

The most recent treatment from 2020 ranked Silphium asperrimum, Silphium dentatum and Silphium simpsonii at species status. 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

Image:Silphium asteriscus-linedrawing.png|Line drawing of Silphium asteriscus

References

{{Reflist|30em}}