California Euphorbs of subgenus Esula

The California Esulas are so much easier than Texas Esulas. The hardest part is that there are so many more observations to go through (in 2017: 1896[Euphorbia] - 1067[Anisophyllum] - 47[Alectoroctonum] - 19[Poinsettia] = 763[Esula]). It's best to start out learning the species in this key: In addition to that, 5 other species are found in CA: E. characias, E. cyparissias, E. exigua, E. serrata, E. amygdaloides, and E. segetalis based on FNA and the observations on iNaturalist. Some of these may only be present in cultivation, but the observations were not clear enough to tell. The characteristics are given below:

E. characias: only species with hairy fruits; dichasial bracts connate (fused together) halfway or more; somewhat similar to E. virgata but larger and has glands without horns or much smaller horns. Based on reviewed iNaturalist observations.
E. cyparissias: like E. virgata, but narrower leaves. Based on FNA.
E. exigua: annual with linear, entire leaves; imagine a linear-leafed E. peplus with acute apices. Based on FNA and reviewed iNaturalist observations.
E. serrata: like E. terracina but without horns on the glands and much deeper serrations on the leaves. Based on FNA; may be extirpated.
E. amygdaloides: like E. characias but with glabrous fruits; dichasial bracts obviously connate about half-way. Unconfirmed outside of cultivation but commonly planted and observed. Based on reviewed iNaturalist observations.
E. segetalis: like E. virgata but appearing stouter with thicker leaves, rougher fruits, and shallowly pitted seeds. Based on reviewed iNaturalist observations.

There are a few other commonly cultivated species that I need to learn just in case. Hopefully, I will get a chance to modify this into a more useful form and put it on the US Euphorbias project.

Other cultivated species:
E. epithymoides
E. lucida
E. x "Blue Haze"
E. mauritanica
E. × martini (E. amygdaloides x characias)

Posted on October 18, 2017 05:56 AM by nathantaylor nathantaylor


Another one that may be in gardens it looks like:

Posted by andy71 about 3 years ago

Thanks! Yeah, it's been a while since I wrote this and haven't updated it. I'm sure there others I could add too (not sure if E. dulcis is sold much out there, but is definitely used in cultivation out east). Unless one of them escapes, I'm not too worried about them.

Posted by nathantaylor about 3 years ago

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