Eriogonum wrightii var nodosum on Cactus Spring Trail, where it is one of two varieties (with membranaceum) of Eriogonum wrightii. Both host the fall-flying blue Euphilotes dammersi dammersi, which times its flight to the bloom of the plants.

Eriogonum wrightii var nodosum. These photos are from October 6, 2019.

This is a female Euphilotes dammersi dammersi that was ovipositing in the flowers of Eriogonum wrightii var nodosum. This species times its emergence from the pupa to the bloom of the flowers so that the larvae can feed on the pollen, then seeds, of the flower over a period of a month or so. The larvae then go to the ground - perhaps underground - to pupate and wait for the next autumn bloom.