Friday, July 21, 2017

A good year for purple and white prairie clover!

The prairies have benefitted greatly by the extensive rains from mid June-late July. Especially, our dry prairies on the South-facing Slope are lusher than we  have ever seen them. Virtually all prairie species are thriving, but two species that are particularly fine this year are purple and white prairie clover (Dalea purpurea and D. candida ). Even before they bloomed there were large amounts of plants on the south slope (Units 2 and 3). A week ago, white prairie clover was in full bloom, and this week it is purple prairie clover, which, because of its color, is spectacular. You can actually tell these two species apart in the vegetative stage, since D. purpurea leaves are smaller and more delicate.

Both of these species are characteristic of dry prairies, with D. purpurea (C value of 7) being more common than D. candida (C value of 8). Since it is a nitrogen-fixing legume, D. purpurea is often added to seed mixes for CRP plantings, although I doubt whether this delicate species adds significant nitrogen to the soil.

D. purpurea was present at Pleasant Valley Conservancy on the south slope (the “goat prairie”; Unit 1) even before restoration began (1995-97), and we have spread it widely from collected seeds. D. candida was not here and was introduced from seeds collected at two high-quality prairie remnants

 
Purple prairie clover on the South Slope. Lots of other species are thriving on this slope, including compass plant, lead plant, spiderwort, and all the warm-season grasses. Note also the oak grubs.

Purple prairie clover

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