In the course of reading "Where the Sky Began" I'm looking up dozens of tallgrass prairie plants on Google Advanced Image Search to see what they look like and whether or not they grow in NE OK.
Also called Wild Alfalfa, Scurf Pea, Slimleaf Scurfpea and Prairie Turnip,they are legumes that grow woodland and woodland edges. They are probably an imported pea family member with summertime alfalfa-like blooms on spikes.
Late summer the stems break and the plant blows - it is related to tumbleweed. We know that tumbleweed is not native to the U.S. either.
Plains Indians made tea from the roots and burned the plant as a mosquito repellent. And, evidently Psoralea is medicinally important in many cultures.
World Wide Science dot org has a gateway to Oklahoma tallgrass prairie articles and information (here) but nothing on this specific plant.
Oklahoma Panhandle State University has a cool site with wildflower photos - full plant, leaves, flowers, etc. Here's their link to Psoralea.
Take a look at these maps - one variety grows all over Italy, too.
|Psoralea mature fruit - photo from OK Panhandle State University|
And, Prairie Moon has a map of the native range of many of its seeds/plants.
|Annie's Annuals calls Psoralea pinnata Kool Aid Bush - this one is a zone 9 plant.|
Internet research reveals that quite a bit of university research is being done on the genus around the world.
Have you ever seen this growing? Have you tried to grow it in a wildlife patch? I'm thinking of buying some seeds to try in the back 40 - well I call it the back 40 - it's really just an acre.