Mystery Plant

I like little mysteries, especially little mysteries that I end up solving without too much hardship. (A little hardship, though, makes it more fun.)

Enter a mystery plant, first noticed (and photographed) a 2 weeks ago in the back 5 acres. Since I walked those acres exhaustively last summer, I was really surprised to see a plant that I'd never seen before back there. Making it even more of a surprise, I saw quite a bit of the plant just on a single walk-through.

I meant to look it up when I got back inside, but got distracted and forgot about it...until the following Tuesday afternoon, when the agricultural extension agent stopped by the Master Gardener HotLine room to show us a sample of Sericea lespedeza, an exotic invasive that is trying hard to take over acres of grassland throughout the Plains. The specimen was dried and pressed, but it looked heartstoppingly like my new mystery plant. Having seen so much of the unidentified forb in the back 5 acres, I dreaded the thought that I might have to try to find some control that wouldn't take out all the rest of the vegetation back there.

Diving onto the web, I exhaustively read everything I could find on Sericea lespedeza. At length I realized that the descriptions talked about seeds that were borne individually, rather than in the dainty little pods that I had seen hanging from the stems of "my" plant. Whew. But what was it?

Tiny white, pink and white, or pinkish flowers, shaped like typical legume blooms....

Those cute little pods hanging down, about 1" long and 1/8" in diameter....

The plant standing about 18" tall, with branching stems and small, compound leaves....

Nothing seemed to fit, so I mentally set it aside for a while. This morning I collected a sample from outback and decided to try again to identify it. After unsuccessfully looking through all my wildflower books, the ones with pretty colored photos and pictures, I finally decided to slog through Bare's Wildflowers and Weeds of Kansas.

There it was - prairie trefoil, now named Lotus unifoliolatus var. unifoliolatus. (It was Lotus purshianus, the old name, in Bare.) Haddock's site on the web (Kansas Wildflowers and Grasses) had it, but his wildflower book did not.

Prairie trefoil is a native annual whose seeds are relished by quail. Being in bean family, I assume it fixes nitrogen, and I'm always glad to welcome native nitrogen fixers to the homestead. It's not the showiest plant on the property, but I'm looking at it as a quiet hard-worker. Tomorrow I'm even going to return the sample stem that I took this morning to the back 5, so that the seeds in the cute little pods can feed quail over the winter or produce new little prairie trefoils next spring. It's another small piece of prairie diversity.