Thank you to DarinAz@Flickr for sharing one of his excellent photographs (contributed via the UBC BG Botany Photo of the Day Flickr Pool | original). Appreciated once again! If you love plants, I do recommend visiting Darin’s photograph sets on Flickr — there’s much to enjoy.
Silver senna or feathery senna is endemic to much of mainland arid Australia, with the exception of the state of Victoria. It seems to have naturalized in both Arizona and California. Previously thought to be a member of the genus Cassia, its former scientific name and related common names (e.g., silver cassia or feathery cassia) still persist in many online references.
The Germplasm Resources Information Network (GRIN) recognizes seven subspecies and three nothosubspecies, or naturally-occurring hybrid subspecies. I’m somewhat confused as the Wikipedia page for Senna artemisioides mentions both a subspecies artemisioides and a hybrid subspecies artemisioides, whereas GRIN only recognizes the latter. What I’m not confused by, though, is the fact that there seems to be much taxonomic work to be done with Senna artemisioides and all of its subtaxa. It seems to me that this is one of those instances whereby the process of presently-occurring speciation is denying taxonomists the ability to sort everything into little boxes.
If you are interested in growing this plant, the Master Gardeners
of the University of Arizona Pima County Cooperative Extension provide this growing guide. FloraBase, the Flora of Western Australia, provides a few more photographs of Senna artemisioides.

Oh, the poor bamboozled taxonomists … 🙂
What a lovely picture, it’s pretty rare for a picture of a plant to be so dynamic!
Oh sorry, yes, I should have put on the Flickr page that this plant is growing at my house in Phoenix. But it’s ubiquitous throughout the Phoenix/Tucson landscapes.
Such a warm colour, and a nicely composed photograph, too. A real pleasure to look at in many ways.
Since it is from Australia and naturalized in Arizona and California, does anyone know whether or not it is noxious (crowding out or replacing native plants)in Arizona/ Calif.?
thank you
the plant in full bloom and grown
is a lovely sight
thank you for the links
Yay GRIN!
I really enjoy getting these photos. I change my wallpaper on my desktop every day so I can enjoy them for a while, and they always give me ideas for my landscape.
You, too, Danny? I change my wallpaper with these amazing photos & learn more about botany. Thought I was the only one. Cool.
Yeah they’re the first big bloomers of the season; and produce copious seed pods. The one in fromt of my house is bowing down under the weight of the green pods this year.
I doub’t they’re very invasive, the one in my yard has been freely blooming and scattering seeds for years and I’ve only ever found a handful of donor plants from it, unlike the bird of paradise plants it’s growing with which are promiscuous as all heck.