Rosinweed, Whole-Leaf Rosinweed, Wholeleaf Rosinweed, Entire-Leaf Rosinweed, Prairie Rosinweed, ETC.

Silphium integrifolium

SIL-phee-um  in-teg-ree(rih)-FOH-lee-um

Synonyms of Silphium integrifolium var. integrifolium (autonym) (4) (Updated on 12-4-23 from plants of the World Online): Silphium integrifolium var. deamii L.M.Perry, Silphium integrifolium var. mesochorum Benke, Silphium integrifolium var. neglectum Settle & T.R.Fisher, Silphium integrifolium var. ternatum Alph.Wood
Synonyms of Silphium integrifolium var. laeve Torr. & A.Gray (3) (Updated on 12-4-23 from POWO): Balsamorhiza silphioides Geyer ex Hook., Silphium laeve Hook., Silphium speciosum Nutt.

Plants of the World Online lists no synonyms for Silphium integrifolium Michx.

Silphium integrifolium Michx. is the accepted scientific name for the Rosinweed. It was named and described by André Michaux in Flora Boreali-Americana in 1803. 

Accepted Infraspecific Names (3) (Updated on 11-30-22 from POWO): Silphium integrifolium var. gattingeri L.M.Perry, *Silphium integrifolium var. integrifolium, Silphium integrifolium var. laeve Torr. & A.Gray. *When an infraspecific taxon is named, an autonym (“type-specimen”) is automatically generated whose description is closest to the (original) species. All have their own list of synonyms. Silphium integerfolium var. integrifolium and Silphium integrifolium var. laeve are found in Missouri, but the latter is not likely in my county. 

Silphium integrifolium var. laeve Torr. & A.Gray is an accepted subordinate species of S. integrifolium. It was named and described as such by John Torrey and Asa Gray in Flora of North America in 1842.

The genus, Silphium L., was named and described by Carl von Linnaeus in the second edition of Species Plantarum in 1753.

As of 12-3-23 when this page was last updated, Plants of the World Online by Kew lists 16 species in the Silphium genus. It is a member of the plant family Asteraceae with 1,702 genera. Those numbers could change periodically as updates are made on POWO. The number of genera in the family fluctuates quite often. 

The above distribution map of Silphium integrifolium is from Plants of the World Online and includes the intraspecific species. The map on the USDA Plants Database is a little different… You can click on the links to go to view the subordinate species own maps. The USDA Plants Database shows two other varieties that are now synonyms… 

The map on iNaturalist shows where members have made observations. Anyone can join and it is a great website to confirm and share your observations. The maps on iNaturalist are continually updated as members post new observations.

THERE ARE SEVERAL LINKS AT THE BOTTOM OF THE PAGE FOR FURTHER READING AND TO HELP WITH A BETTER POSITIVE ID.

There are always quite a few Silphium integrifolium growing along the edge of the south hayfield. They are impressive plants that always make a statement. Common names include Rosinweed, Wholeleaf Rosinweed, Whole-Leaf Rosinweed, Entire-Leaf Rosinweed, Prarie Rosinweed, and probably others. They are a common sight along highways, backroads, and trails.

I apologize for not writing descriptions at the moment. I am busy updating plant pages and writing new pages for wildflowers I identified over the summer (plus adding more photos to previously published pages). Writing descriptions in my own words can be a lengthy process, so I decided to just make new pages and come back later and write the descriptions. This is a winter project but sometimes I get behind and it takes longer. I need to continually update because plant names change, the number of species and genera fluctuates, and I want to be as accurate as I can. There are several very good websites below that can help with a positive ID. We are all a work in progress.

The Missouri Plants website says both Silphium integrifolium var. integrifolium and Silphium integrifolium var. laeve are found in Missouri. Silphium integrifolium var. integrifolium has glaucous and glabrous (smooth) stems and involucres while S. integrifolium var. laeve has pubescent stems and involucres (short hairs). In other words, the stems are either rough or smooth and appear to have a chalky coating (from the short hairs)… HOWEVER, Silphium integrifolium var. laeve is NOT likely found in the county I live in…

 

 

 

 

A while after the hay was cut in 2020, I noticed a few plants growing in the hayfield trying their best to grow, flower, and go to seed before the season was over.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

This colony was growing a little weird because it was mowed when the hay was cut. It re-grew as a shorter plant with leaves closer together.

 

 

 

 

I have enjoyed photographing and learning about the many wildflowers growing on the farm and in other areas. The farm where I live is in Windsor, Missouri in Pettis County (Henry County is across the street, and Benton and Johnson aren’t far away). I have grown over 500 different plants and identified over 250 species of wildflowers (most have pages listed on the right side of this site). I am not an expert, botanist, or horticulturalist. I just like growing, photographing, and writing about my experience. I rely on several websites for ID and a horticulturalist I contact if I cannot figure them out. Wildflowers can be somewhat variable from location to location, so sometimes it gets a bit confusing. If you see I have made an error, please let me know so I can correct what I have written.

I hope you found this page useful and be sure to check the links below for more information. They were written by experts and provide much more information. Some sites may not be up-to-date but they are always a work in progress. If you can, I would appreciate it if you would click on the “Like” below and leave a comment. It helps us bloggers stay motivated. You can also send an email to me at thebelmontrooster@yahoo.com. I would enjoy hearing from you especially if you notice something is a bit whacky.

FOR FURTHER READING:
PLANTS OF THE WORLD ONLINE (GENUS/SPECIES)
INTERNATIONAL PLANT NAMES INDEX (GENUS/SPECIES)
TROPICOS (GENUS/SPECIES)
FLORA OF MISSOURI (GENUS/SPECIES)
WORLD FLORA ONLINE (GENUS/SPECIES)
FLORA OF NORTH AMERICA (GENUS/SPECIES)
WIKIPEDIA (GENUS/SPECIES)
USDA PLANTS DATABASE
MISSOURI BOTANICAL GARDEN
MISSOURI PLANTS
MISSOURI DEPARTMENT OF CONSERVATION
iNATURALIST
WILDFLOWER SEARCH
DAVE’S GARDEN
ARKANSAS NATIVE PLANT SOCIETY
ILLINOIS WILDFLOWERS
MINNESOTA WILDFLOWERS
KANSAS WILDFLOWERS AND GRASSES
KANSAS NATIVE PLANTS
NORTH CAROLINA STATE UNIVERSITY
PFAF (PLANTS FOR A FUTURE)
LADY BIRD JOHNSON WILDFLOWER CENTER
FRIENDS OF THE WILDFLOWER GARDEN
OZARK EDGE WILDFLOWERS
GARDENIA

NOTE: The data (figures, maps, accepted names, etc.) may not match on these websites. It depends on when and how they make updates and when their sources make updates. Some websites have hundreds and even many thousands of species to keep up with. Accepted scientific names change periodically and it can be hard to keep with as well. Some of the links may use a name that is a synonym on other sites. In my opinion, Plants of the World Online by Kew is one of the most reliable and up-to-date plant databases and they make updates regularly. I make updates “at least” once a year and when I write new pages or add new photos but I do get behind. We are all a work in progress. 🙂