Green Poinsettia, Toothed Spurge, Toothedleaf Poinsettia, Eastern Toothed Spurge

Euphorbia dentata

yoo-FOR-bee-uh  den-TAY-tuh

Synonyms of Euphorbia dentata (7) (Updated on 1-25-22 from Plants of the World Online): Anisophyllum dentatum (Michx.) Haw., Euphorbia aureocincta Croizat, Euphorbia dentata var. linearis Engelm. ex Boiss., Euphorbia fontanesii Steud., Euphorbia herronii Riddell, Euphorbia purpureomaculata T.J.Feng & J.X.Huang, Poinsettia dentata (Michx.) Klotzsch & Garcke

Euphorbia dentata Michx. is the accepted scientific name for this species of Euphorbia. It was named and described as such by André Michaux in Flora Boreali-Americana in 1803.

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

As of 1-25-22 when this page was last updated, Plants of the World Online lists 2,028 species in the Euphorbia genus. It is a member of the plant family Euphorbiaceae with a total of 227 genera. Those numbers could change as updates are made on POWO. The number of species in the genus fluctuates often.

The above distribution map for Euphorbia dentata is from Plants of the World Online. Areas in green are where the species is native and purple where it has been introduced. The map on the USDA Plants Database for North America is a little different and the BONAP map is more in line with POWO…

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.

You never know where an interesting wildflower is going to show up. There are 40 acres here on the farm and where did this one pop up? In the basement of the old foundation where my grandparent’s house used to be. I have never seen it anywhere else here and it always makes me wonder how it even got where it was in the first place… I didn’t climb down in the basement with it. I just zoomed in the best I could and took A LOT of photos then selected a few that came out well.

Euphorbia dentata is an annual wildflower that grows throughout Missouri and much of central United States eastward (plus California) where it is either native or has been introduced. The map on POWO also indicates the species is a native of Northeast Mexico and has been introduced in Ontario in Canada and north-central China.

Information states this species likes full sun in just about any soil, although it supposedly prefers poor soil with plenty of clay, sand, or gravel. Where I found it was close to the corner in the basement of the old foundation where it likely didn’t get full sun. It was growing on top of old boards and the only soil it had was from decaying plant matter. It still baffles me how its seeds got down there anyway and germinated… Otherwise, it can be found along streambanks, forests, glades, upland prairies, fields, pastures, gardens, and so on… 

Hopefully, the Euphorbia dentata will return in 2022. If it does, I will climb down in the old foundation to get more photos. If not, I will be saying “I should have done that last year.”

Euphorbia dentata grows up to 2’ tall in favorable conditions and grows from multiple stems from the base and branches out somewhat. Stems are green, yellowish-green, sometimes reddish-green. The stems are densely pubescent with short downward facing hairs. It can also have scattered longer multicellular hairs.

The leaves of Euphorbia dentata are highly variable. For the most part, they grow in an opposite manner but can be alternate. They can be linear, lance-shaped (lanceolate), to nearly circular in outline, 3/4-3” long x 1/4-1” wide, tapered at the base with petioles, bluntly pointed at the tip. Leaf margins can be coarsely or finely toothed and even fairly smooth, scalloped or wavy. The surfaces of the leaves are sparsely to densely hairy (pubescent). They can be green, grayish-green, and can be reddish to purplish tinged. Leaf undersides are paler than the upper surface.

The flowers are somewhat hard to explain. The stems of the plant are topped with 1-3 clusters of cyathia each with 25-40 staminate flowers and immature fruits.

I was writing a post about “I should have” and what if” using the Euphorbia dentata as an example. I “should have” went ahead and climbed down into the basement to get better photos in September 2021 when I first found this species. Then I got to thinking “what if” seeds don’t come up in 2022. After all, I found this plant n the basement of my grandparents old home where there is not much but old boards and brush. The odds aren’t very good. So, I got up, grabbed the camera, then went to the garage and got the ladder. I put the ladder close to where I found the Euphorbia dentata, and a little to the left and I would have been on top of it…

I pulled off several of the dried up flowers but still left more than I took.

Once I brought my find to the house, I crumbled up everything and started looking for seed. Sorry the photo is a little blurry, but those seeds are only 2-3 mm long… The ruler is on the metric side. Now that I have a few seeds, I will see if I can get them to come up in the spring in a better place than in the old foundation.

Hopefully next year I will have a few plants coming up somewhere besides in the old foundation.

I have enjoyed photographing and learning about the many wildflowers growing on the farm and other areas. My farm 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 100 species of wildflowers (most have pages listed on the right side of the page). 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 few horticulturalists 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 NORTH AMERICA (GENUS/SPECIES)
WORLD FLORA ONLINE (GENUS/SPECIES)
WIKIPEDIA (GENUS/SPECIES)
USDA PLANTS DATABASE
DAVE’S GARDEN
MISSOURI PLANTS
UNIVERSITY OF MISSOURI
iNATURALIST
WILDFLOWER SEARCH
ARKANSAS NATIVE PLANT SOCIETY
ILLINOIS WILDFLOWERS
MINNESOTA WILDFLOWERS
KANSAS WILDFLOWERS AND GRASSES
GO BOTANY
LADY BIRD JOHNSON WILDFLOWER CENTER
MARYLAND BIODIVERSITY PROJECT
BACKYARD NATURE
VIRGINIA TECH

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 the most reliable and up-to-date plant database and they make updates on a regular basis. 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. 🙂