Oxytropis campestris (see comments) not Astragalus sp., a yellow flowers species from Wyoming....I love silvery tufting plants

Scott, GrayC, and Kevin T brought the seeds back from their prairie/badlands/... collecting trip. Among their targets, were plants that could potentially be used on green roofs. Brad germinated the seeds, and grew the plants. Some are now planted in a cold frame with soil amended for maximum drainage. It's a beautiful little clumpy rosette, a silver tuft, in the Fabaceae. I have it as Astragalus agrestis, the Purple Milkvetch....a yellow flowered form I suppose.. I'll check the label tomorrow. The genus is astoundingly large; The Wikipedia article quotes a paper by David G Frodin (2004) suggesting there are around 3,000 species in Astragalus. Wow.