Croton michauxii var. ellipticus (Syn. Croton willdenowii-Common Rushfoil)-Michaux’s Croton

Croton willdenowii (Common Rushfoil) on 9-6-18, #503-24.

Michaux’s Croton

Croton michauxii var. ellipticus

KROH-ton  miss-SHOW-ee-eye  var.  ee-LIP-tih-kus


Common Rushfoil

Croton willdenowii

KROH-ton  wil-den-OV-ee-eye

Synonyms of Croton michauxii var. ellipticusCroton willdenowii G.L.Webster, Crotonopsis argentea var. elliptica (Willd.) Pursh, Crotonopsis elliptica Willd., Leptemon ovalifolium Raf., Leptemon verrucosum Raf.

I first identified this plant as Croton willdenowii G.L.Webster. The species was named and described by Grady Linder Webster in Novon in 1992. This name is now considered a synonym of Croton michauxii var. ellipticus. Steyermark’s Flora of Missouri (volume 2, 2006) describes seven species of Croton in Missouri (U.S.A.) including Croton michauxii and Croton willdenowii. The Missouri Plants website only has information on four species and does not include Croton michauxii. The administrator of the site told me earlier he had a lot of updates to make over the winter. The link for Missouri Plants at the bottom of the page will take you to Croton willdenowii

Croton michauxii var. ellipticus (Willd.) B.W.van Ee & P.E.Berry is the correct and accepted scientific name for this variety of Croton. It was named and described as such by Benjamin William van Ee and Paul Edward Berry in Harvard Papers in Botany in 2009. It was first named and described as Croton elliptica by Carl Ludwig Willdenow in the fourth edition of Species Plantarum in 1805.

Ummm… Crotonopsis elliptica Willd. is also in the mess because this particular plant has one-seeded fruit, along with the former Crotonopsis linearis, etc. SO, at one point, the plants with one-seeded fruit were separated into the Crotonopsis genus. However, the Croton genus was reclassified to include plants with 1, 2, and 3 seeded fruit. SO, that has led to Crotonopsis elliptica becoming a synonym of Croton michauxii var. elliptica. Croton wiildenowii and Crotonopsis elliptica were apparently the same so they both become synonyms. Crotonopsis linearis now a synonym of Croton michauxii. The other accepted Croton michauxii variety, Croton michauxii var. michauxii has two Crotonopsis synonyms… I am to confused now to go into that besides I never have been able to figure out how a species and variety name can be the same.

ALSO, a member of iNaturalist suggested the plant I observed could be Croton glandulosus. GEEZ!!!

The genus, Croton L., was named as such and described by Carl von Linnaeus in the second volume of the first edition of Species Plantarum in 1753. According to Plants of the World Online by By Kew, there are 1,158 species in the Croton genus (as of 2-14-20 when I am updating this page. Down five from the last time I checked). Croton is a member of the Euphorbiaceae Family along with 226 other genera. Those numbers could change… Again.


Distribution map of Croton michauxii var. ellipticus from Plants of the World Online. Facilitated by the Royal Botanic Gardens, Kew. Published on the Internet; Retrieved on February 14, 2020.

The above map from Plants of the World Online is the same as the map provided on the USDA Plants Database. Both sites list Croton michauxii var. ellipticus as the accepted name with Croton willdenowii as a synonym.

There are several links at the bottom of the page for further reading and help you get a positive ID.


Croton willdenowii (Common Rushfoil) on 9-6-18, #503-25.

I took these photos from a few plants I found growing in one small area in the pasture in the back of the farm. Our farm is in Pettis County in west-central Missouri. Henry County is across the street. The pasture was used for hay in 2019 so I didn’t get to check on this plant until after the hay was cut. Unfortunately, I didn’t see any. I will keep an eye on the area better in 2020 because I need MORE photos to write better descriptions.

Some of the links below will take you to pages that use the name Croton willdenowii and others Croton michauxii var. ellipticus. Sites that list C. willdenowii as accepted say the other is a synonym and visa versa. It takes A LONG TIME for some websites and databases to update when names change. Some never do update once they write a page and some sites are even unmaintained but they are still online. Some will probably continue using the old name, which is supposedly OK since there is no “law” against it. 🙂 I try and keep my site updated even though sometimes I may not agree. I am not a horticulturalist or botanist, so why should I object. Anyway, sometimes I get behind even with my small site. I can imagine how it would be if I had several thousand names to change.

I vented a little then deleted what I wrote… We have to be patient and let the”people in charge” of name changes sort through the multitude of plants that have multiple scientific names. I am sure there are plenty of disagreements. Whether you choose to call this plant Croton willdenowii or Croton michauxii var. ellipticus is up to you. :).

So, hopefully, I will find more of this plant in 2020 so I can add more photos and give better descriptions.

I have enjoyed photographing and learning about the many wildflowers growing on the farm and other areas. I have grown over 500 different plants and most have pages listed on the right side of the blog. 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. 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 I would enjoy hearing from you.