Epimedium

I can't believe I have not blogged about Epimedium since May 2008.  I felt for sure I had touched on this plant since starting Planted Cloud.  In any case, I was in Dumbarton Oaks a few weeks ago and was struck once again at how lovely the fall color is on this herbaceous groundcover.

Back in 2008, I did touch on the medicinal history for Epimedium -- the common name is barrenwort, and it was presumed that ingesting this would help with impotence, thus solving the 'condition' of barrenness.

I'm not naming a species here, as there are over 60 in cultivation.  Most commonly however would be E. x rubrum.  Below is one such species in the spring.  You can see how strikingly different even the greens are among these two specimens in spring and fall.  Regardless of species, Epimedium usually has chartreuse new leaves that are somewhat soft in texture.  By autumn, the leaves become more leathery and darker green.

Euphorbia amygdaloides var. robbiae

Last night was my first day of class back at the program in DC -- this semester I'm teaching a perennials for fall course, which I suspect will include no shortage of wonderful grasses and ferns.  

In the meantime, we did take a look at this handy groundcover -- Euphorbia amygdaloides var. robbiae.  The common name, besides Robb's Euphorbia, can also be wood spurge, which led to some confusion last night, since that is also a name for the native Pachysandra, P. procumbens.. Add to that, this plant is similar(ish) to Pachysandra, in that it's an evergreen groundcover that spreads easily and quickly.

Of course, the radial leaf arrangement (the almond shape of the leaf accounts for the species name amygdaloides which means almond-like) is quite different and this plant has tall spikes of yellow flowers in the spring.  The flowers (which are most noticeable due to their showy bracts and involucres) persist for several weeks in the spring.

Vinca minor

These pics were also taken during the run I mentioned in yesterday's post.  I had passed by this modest little stand of Vinca minor several times already and kept putting off getting a few pictures of it.  Honestly, I thought I'd encounter a better use of this common groundcover...but why put off til tomorrow what you can do today?

As I mentioned, this plant is often used as a groundcover, actually, I think it's only used as a groundcover.  And as far as groundcovers go, I rank this high above Pachysandra or Hedera helix.  The flowers are pretty in the spring, much more attractive than Pachysandra and it's not likely to take over your landscape (and buildings) the way English ivy would. 

 

That said, it is noted by some as invasive, though I've personally discovered its relative, Vinca major 'Variegata' to be far worse.  My folks put some in planters in their backyard once and in the fall, dumped the soil, which contained a few of the variegated vines.  They overwintered and began to colonize the backyard.  We're steadily removing them now.  

Vinca is in the Apocyanaceae or dogbane family.  The flowers are fairly distinctive among this family which includes Plumbago auriculata and Alyxia ruscifolia.

Microbiota decussata

In November, I made a reference to Louise Bourgeois's spider sculptures.  Now you can decide for yourself whether or not that big katsuratree in Dumbarton Oaks resembles one of her sculptures.  I still think it does.  

In any case, this isn't an art blog, so we won't spend too much time on the actual sculpture.  Instead, we're noting the groundcover beneath it: Microbiota decussata, or Siberian cypress.

Siberian cypress was discovered outside Vladivostock in 1921, growing above the tree line of nearby mountains and withstanding temperatures below -40° F.  Since then it's been a favored cypress family groundcover, less common than Juniperus and just a tiny bit more tolerant to light shade. It also (similar to blue rug Juniper) changes color.  In the winter, as you can see it has a dusky rose tint, but when the weather warms up, it will turn green.  If you read my NYPAOS post on fall color, you will know that this change in color means that the chlorophyll is no longer being produced and thus the green pigment in chlorophyll is not abundant, providing opportunities for the anthocyanins in the plant to be reflected in the color spectrum.

Though the plant can handle a touch more shade than Junipers (the only other Cupressaceae genus with popular groundcovers), it is demands of good, well-drained but moist soil.  This is also about as far south as the plant can be.  In zones 8 and warmer, it simply does not survive.