Horseweed, Marestail, Horsetail, Canadian Horseweed, Canadian Fleabane, Fleabane, Hogweed, Coltstail, Butterweed
Erigeron canadensis L.
Syn. Conyza canadensis (L.) Cronquist
Synonyms of Erigeron canadensis: Aster canadensis (L.) E.H.L.Krause, Caenotus canadensis (L.) Raf., Caenotus pusillus Raf., Conyza canadensis (L.) Cronquist, Conyza canadensis var. glabrata (A.Gray) Cronquist, Conyza canadensis var. incisa P.D.Sell, Conyza canadensis var. obovoidea P.D.Sell, Conyza canadensis var. pusilla (Nutt.) Cronquist, Conyza canadensis var. robusta P.D.Sell, Conyza canadensis var. simplex P.D.Sell, Conyza parva Cronquist, Conyzella canadensis (L.) Rupr., Erigeron canadensis var. glabratus A.Gray, Erigeron canadensis var. pusillus (Nutt.) B.Boivin, Erigeron myriocephalus Rech.f. & Edelb., Erigeron paniculatus Lam., Erigeron pusillus Nutt., Erigeron ruderalis Salisb., Erigeron strictus DC., Inula canadensis Bernh., Leptilon canadense (L.) Britton, Leptilon canadense var. pusillum (Nutt.) Daniels, Leptilon pusillum (Nutt.) Britton, Marsea canadensis (L.) V.M.Badillo, Senecio ciliatus Walter, Tessenia canadensis (L.) Bubani, Trimorpha canadensis (L.) Lindm.
Erigeron canadensis L. is the correct and accepted scientific name for this plant. The genus and species were named and described as such by Carl von Linnaeus in the second volume of the first edition of Species Plantarum in 1753. Many websites use the name Conyza canadensis (L.) Cronquist which was named and described as such by Arthur John Cronquist in the Bulletin of the Torrey Club in 1943. The other websites have either not updated the name or they choose to use Conyza canadensis. Maybe they didn’t get the memo. 🙂 I generally stick with what Plants of the World Online says because I think they are the most up to date database.
Plants of the World Online lists 454 species in the Erigeron genus (as of 2-10-20 when I am updating this page). Erigeron is a member of the Asteraceae Family along with 1,763 other genera. Those numbers are likely to change.
As you can see by the map above provided by Plants of the World Online, with permission, Erigeron canadensis is a very widespread species. Areas in green are where it is native and purple is where it has been introduced. It could be more widespread and not reported.
Hardly anyone in rural areas or even in the city has not come across the Horsetail. They grow just about anywhere, even in cracks in sidewalks, alleys, along backroads, old foundations, fence rows… You get the picture. The species has many common names including Horseweed, Marestail, Horsetail, Canadian Horseweed, Canadian Fleabane, Fleabane, Hogweed, Coltstail, Butterweed and maybe others.
Erigeron canadensis is an annual weed with a strong ascending growth habit. They generally start branching out toward the upper part of the stem and produce LOADS of flowers and seeds. The long, lance-shaped leaves are arranged in an alternate pattern along the stems. The stems and leaf margins are covered with white hairs.
The multitude of flowers produce seeds which are carried through the wind.
I am not going to go into great detail with technical language because this plant is very easy to identify. If you want a complete description you can check some of the links below.
I find it very interesting this plant is edible, so be sure to check out the link below to EDIBLE WILD FOOD.
Remember if you are doing research about this plant it can be listed as either Conyza canadensis OR Erigeron canadensis. Who knows which name will eventually win the prize…
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 email@example.com. I would enjoy hearing from you.