notes Detail of two flowers of Frasera albomarginata...which is the current name for what some may know from the recent past as Swertia albomarginata (although Frasera is the original generic name Sereno Watson gave it way back in 1871).
I was delighted to find this in the wash on the way back down Keystone Canyon...I missed it on the way up. This was the only (non-rosette stage) Frasera plant I saw, and (thankfully) it still had flowers when I encountered it on Sept. 23, after recent monsoonal rains.
This species is monocarpic: meaning it grows for a number of years as a rosette; then, when conditions are right, sends up a flowering shoot; and, after the fruit and seeds develop, it dies (i.e. the plants produce flowers & fruit only once). So a typical population will have more rosettes than plants in flower.
F. albomarginata is an uncommon species in CA, and I had never seen it before...though I had read about it on the (very informative!) web pages at Tom Schweich's site, and remembered that it had known stations in the Mid-Hills SW of the the New York Mnts, and also much further NW in the Last Chance Range. Later I learned it has a number of vouchers from the Keystone Canyon area, as well as the Clark Mnts to the north (see here, and a CalPhotos post from Jim Andre).
CalFlora indicates a flowering period of May to August, and most of the CCH records for this species are from May to June, with one Keystone Canyon record from July 30. Other than this sighting, the latest seasonal record (with flowers) in CA that I could find was Sept. 2, from the Clark Mountains. The photograph here was taken 3 weeks later than that.
According to this SEINet web page, F. albomarginata is more abundantly distributed to the east of CA in NV, UT, AZ, and also just making it into far southwestern CO and (barely!) into the northwestern corner NM.
While I could find no specific flower record later than Sept. 23, the diagram at the lower left of the webpage here indicates there are a few flowering records of F. albomarginata from late September (and even October and December)...though it gives no specifics on where the records were taken, or the herbaria where those records are found. Tom's Schweich's web page of the geographic distribution of F. albomarginata has incredibly abundant and detailed info, but I couldn't find an indication of the latest date of flowering he had encountered in his (quite exhaustive) study of this species.