Euphorbias are a complicated lot, and though I grow five different varieties in my garden (and once briefly a sixth, Euphorbia griffithii) I'm making educated (or otherwise) guesses as to their correct names.
But first, a general comment. I grow the soft-stemmed perennials, not the succulents, and they've been brilliant foliage plants for 'landscaping'. In other words, I've planted one and seedlings have popped up here there and everywhere. Or the original single plant has spread itself and filled up a whole garden, looking good enough when in flower to be ignored.
I suspect the larger Euphorbias are 'characias'. Or 'wulfenni'. I can't quite tell the difference. Oops. If there is indeed a difference.
All my Euphorbias have such a freshness in spring, with beautiful yellow-green flower spikes. The gaudiest and brightest is Euphornia polychroma. That's what I've always called it. This seeds prolifically - such a nuisance if you want to control your garden, but a blessing if you don't and the area in question is difficult, plantwise.
My larger shrubs ('characias' or 'wilfenni') are taller, upright, with beautiful blue-green foliage. They seed a little, but not a problem. I love the blue-green foliage contrasting against the lime-yellow flowers. Well, I call them flowers - oops.
Now on to the little Euphorbias. E cyparissias Fens Ruby is one such, a so-called ground-cover. It's ferny, and spready (it does get about a bit). But really very pretty, and easy to pull up, so I'll say no more.
The original Euphorbia cyparissias is uber-invasive, with coarser green leaves. This I could possibly do without. A friend gave me a wee piece and didn't warn me, so I planted it in the Dog-Path Garden. Luckily this isn't an area I've ever wished to control, because E cyparissias has taken over. The flowers appear on stems about 30cm high, and the plant spreads strongly from rhizomes - into the next garden, under a path, into a lawn, wherever. A friend, was she?
Euphorbia with Coprosma
Another little one is the ground hugging Euphornia myrsinites, and friends have warned me about it being a particularly nasty skin irritant. I've not had this problem, and it's so pretty, so I rather like it. Many of the herbaceous, leafy Euphorbias are commonly called 'spurges' - this one gets the name 'Donkey Tail Spurge'. It's on the noxious pest list in some places because of self-seeding.
All my Euphorbias have milky white sap in their stems - it's toxic, and awful if you splash any in your eyes, even the tiniest drop. One day while trimming E polychroma I accidentally rubbed my face. Aargh! I bathed my eyes and sulked for the next three hours.
euphorbia from the bargain bin
A couple of variegated varieties are definitely on my wish list - Burrow Silver (a characias) and Ascot Rainbow (a martini). Watch this space! And check out this groovy Euphorbia website for some detailed botanical infornmation.