Al Deurbrouck and I(Len Lehman) are looking for a small indigofera that grows only 2-3 inches tall and tends to be a matt former! If anyones knows the species name and sources of plants and/or seed in US, please let me know!
We would like to put it in the public rock garden we sposer at the National Aviary in Pittsburgh!
Len Lehman
Just to introduce a weird note into the forum. I was given a large supply of old seed, and am testing it for viability.
Picture of two nicked and soaked twenty-year-old seeds of Astragalus sobolevskiae, JJH 951081. I could find nothing at all about this species, other than it was described by Antonina Vasilevna Polozhij (1917-2003), and then collected by Halda at 2400 meters in the Altai.
Obviously, a plant so rare, it's never even heard of itself.
"We will sow no seed before its time."
One of the highlights of the 2014 growing season was the spectacular bloom of Astragalus loanus in May.
I ended up with two plants, from the seed started in spring, 2012. Seed was from the NARGS seedex, and germinated in 9 days at room temperature after it was scarified. (I probably didn't scarify it too effectively; had I done so, I imagine it likely would have germinated much more quickly.) There was a small bloom in the second year from seed, but it really outdid itself in the third year from seed.
Another interesting Astragalus. This is A. ceramicus, it is very nice in bloom but i did not catch it in time but it has these big inflated and sometimes colorfull pods. I took this picture this afternoon. 
A native plant in bloom (a little past its peak) on June 28th in the grasslands in Bowmont Park, Calgary:
This Oxytropis species is found across a vast expanses of North America. There are currently five recognized varieties. Varieties borealis, hudsonica and sulphurea are restricted to boreal enviroments of AK and the Canadan provinces and territories of QC, ON, MB, NT, YT, BC, AB and NU.
This high elevation Lupin is quite common at high elevation in the southern Cascade and Sierra Nevada Ranges. It is found at elevations of 4,000'-13,000' (1,220-3,960 m) on well drained slopes and ridges often in open forested sights. The growth on lean scree sights is very short and tight with the foliage 1/2" (1.27 cm)tall and the inflorescence hovering an 1"(2.54 cm) above. In richer sights the plants grow twice that size. The woody crowns and branches tend to be buried by wind blown soils, these branches will send up leaves several inches away from the crown.
A striking matted milkvech from the Great Basin and Desert Southwest, Astragalus calycosus grows at elevations of 3000'-8000' (915-2438m). There are three varieties listed for the species Astragalus calycosus var. calycosus, var. monophyllidius, and var. scaposus. Flowers colors range from white/cream, through pink and purple.
The variety I am familiar with is Astragalus calycosus var. calycosus. I have not yet had the opportunity to grow this one but have hopes of finding seed one day.
Astragalus whitneyi, the balloonpod milkvetch, is a mid to high elevation tufted perennial. There are five varieties listed, Astragalus whitneyi var. confusus, var. lenophyllus, var. siskiyouensis, var. whitneyi and var. sonneanus. Found on desert mountains along the eastern escarpment of the Cascade/Sierra Nevada crest. Starting in Washington going south to northeastern California, western Nevada and continuing east to southwestern Idaho.
I grow a variety of Astragalus newberryi. There are five varieties in this group aquarii, blyae, castoreus, escalantinus, and newberryi. I grow variety castoreus the most widespread.