Gagea serotina / Snowdon lily
Also known as: mountain spiderwort, common alplily, Snowdon alplily—or in Welsh, brwynddail y mynydd (“rush-leaves of the mountain”), late-flowering star of Bethlehem
Synonym: Lloydia serotina (and 25 more)
Snowdon lily is a perennial growing from a bulb. For most of the year, it just looks like a thin group of long, curving, a bit stiff, grass-like leaves. It may grow up through cushions of other plants, or out of rock fissures (as in the photos here).
In the Tetons, it flowers in July to early August. The flowers occur singly at the end of long stalks. They are white with blue/purple or reddish veins along the six tepals. The flowers have nectaries at the bases of the tepals, encouraging insect pollination.
Snowdon lily is widespread but not common in the mountains of western North America, from Alaska to New Mexico, but is limited to arctic and alpine zones. Indeed, IDFG does not even list it in Idaho. It also has a surprisingly wide distribution in similar zones throughout the northern hemisphere. The genus and species probably originated in SW Asia and migrated to North America during the Pleistocene via the Beringia land bridge… so sometime between 2.5 MYA and 12,000 years ago.
Interesting bits: Snowdon lily is expected to be the first plant that will go extinct in Britain as a result of global warming. Because its range is limited to inaccessible high areas, it will not migrate on its own. Therefore, there are schemes in the works to introduce it to remote sites in Scotland. Actually, its existence in Britain is itself weird, being a glacial relic that is now genetically distinct from populations in continental Europe. Its current rare status is attributed to overgrazing by sheep.