Some desirable forbs of oak savannas

The most recent USDA-NRCS plan for Wisconsin's WHIP program (WHIP = Wildlife Habitat Incentives Program) places oak savanna restoration at the top of the list and calls attention to a number of priority forbs species. I was pleased to find that we already have most of these priority species at Pleasant Valley Conservancy, in some cases in substantial numbers. The list is given below:

yellow pimpernel: Taenidia integrifolium
pale Indian plantain: Arnoglossum atriplicifolia
woodland thistle: Cirsium altissimum
silky rye: Elymus villosus
elm-leaved goldenrod: Solidago ulmifolia
New Jersey tea: Ceanothus americana
upland boneset: Eupatorium sessilifolium
horse gentian: Triosteum perfoliatum
purple milkweed: Asclepias purpurascens
wild hyacinth: Camassia scilloides

We had small populations of most of these even before we started restoration, and by collecting seed and spreading in newly restored areas we have obtained much larger populations. Two that we did not have, pale Indian plantain and woodland thistle, are now growing. Pale Indian plantain is thriving all over the savanna areas, as well as in the mesic and wet-mesic areas of our planted prairies. We also have woodland thistle growing, but since it is a biennial, it is taking us longer to get thriving populations.

As readers already know, we have some pretty good native populations of purple milkweed (Endangered in Wisconsin), which have responded well to savanna restoration. Wild hyacinth (also Endangered here), is still missing and is going to be one of our targets in the next several years. Although fairly restricted in Wisconsin, at one time there were some reasonable roadside populations of this species, and a commercial seed source is available. We'll see!

I'm not sure who came up with this species list. Several species listed are fairly common and may be on the list mainly because they are savanna "indicator" species. Horse gentian, New Jersey tea, elm-leafed goldenrod, and silky rye are pretty common, and I have seen sites that have very large amounts of upland boneset.