Lousewort effect on Carex

In an earlier post I discussed the hemiparasitism of wood betony and how it often acts on prairie grasses. I have now found a similar phenomenon in the related species lousewort (Pedicularis lanceolata), which thrives in wetland situations. I have now found that the clonal sedge Carex trichocarpa, which has been spreading into one of our wet prairies, is being parasitized by lousewort, offering the hope that the sedge will be kept in check. The photo above shows a large patch of the sedge within which there is a distinct "hole" that has been created by growth of lousewort.

The photo to the left shows the lousewort plants close up.

According to the literature, the small roots of the lousewort are able to penetrate roots of other species and obtain part of their nutrients from them. The hole shown in the top photo indicates how effective this parasitism is.

Lousewort in our wetland is a very prolific seed producer and we plan to collect seed this fall and plant among the sedge clones.