Wood betony time

Wood betony (Pedicularis candensis) is an interesting species that is found in prairies and open wooded thickets throughout Wisconsin. Wood betony grows in hemiparasitic fashion upon the roots of grasses or other herbaceous plants. Because of its parasitic property it is able to exert considerable control on surrounding plants, and has hence been called a "keystone" species. (See Rich Henderson's paper on keystone species in the 18th North American Prairie Conference, available digitally through the U.W. Madison Digital Collections.) According to Henderson, there is a good probability that the presence of a keystone species such as wood betony will markedly enhance the diversity of a prairie or savanna site.

We had a few small native populations of wood betony at Pleasant Valley Conservancy, and have been working to extend these by spreading seeds.

This is the time of year when wood betony is very visible. It grows in patches and its light yellow color makes it easy to spot, even from a distance. Today we found it in a couple of our savanna areas as well as in two planted prairies, the Pocket Prairie and Toby's Prairie. The photos here, taken by Kathie, are from Toby's.

According to Henderson, wood betony particularly parasitizes grasses, and it is probably because of its reduction in prairie grasses that it increases diversity in prairie remnants. (The elimination of grass patches results in the presence of bare areas, where other prairie plants can become established.)

In planted prairies of extended age, large grass-free "holes" may be seen where wood betony has become well established.

If you can find a seed source (it is also available commercially) collect around the end of June. Throw seeds out in areas with heavy populations of grasses. Establishment may take some time, and the population will move around, since once it kills off its grass host it dies back, only to reappear in other grass areas.

The related species P. lanceolata, which is also common in our area, thrives in wet-mesic to wet areas, where we find it attacking clonal sedge species such as Carex trichocarpa.