disk pappus 1.5-2 mm. Counted 48 plants in a ~100m radius, and found none outside that area. The largest was nearly 5' tall. Smelled like really good honey. Associated/nearby plants: Grindelia, Malvella leprosa, Epilobium brachycarpum, Lepidium latifolium, Frankenia, and of course Centaurea solstitialis