basalt-substrate close to conifer stands. In addition to a variety of grasses, the surrounding vegetation includes western monkshood, Hooker's and arrowleaf balsamroot, redstem ceanothus, pinkfairies, hairy clematis, dwarf larkspur, parsnipflower buckwheat, fernleaf and nineleaf biscuitroot, sulphur lupine, beardtongues species, virgate scorpion-weed, sticky and slender cinquefoil, sagebrush buttercup, dwarf and Nootka rose, common snowberry, American vetch and northern mule's ears. Brown's peony avoids drought by dying down completely in early summer, after flowering and surviving underground with stores of nutrients and energy in its thick rootstock. When parts of the plant are broken, bruised or damaged by predation it produces a pronounced bitter and unpleasant scent. Plants are rarely eaten, but caterpillars of the species Euxoa ustula, dark grey fishia and small heliothodes moth have been found to eat 1–2 mm holes in the flowers, although these species are better known from other host plants. Flowers give off the same smell more weakly and the lobes of the disc secrete a sweet nectar with a bitter aftertaste over the entire time the stigmas and anthers are fertile. Pollination According to one source, wasps, such as the common aerial yellowjacket and Polistes aurifer, and sweat bees, in particular, Lasioglossum species, make up the majority of pollinators, in addition to hoverflies such as Criorhina caudata. Bernhardt et al., after studying an endemic population in Oregon's Blue Mountains, stated: Although this plant produces a significant amount of pollen, the insects that pollinated it sought it for nectar. The study's authors argued that it is unlikely that the vespid wasps co-evolved with the plant, although they do benefit it by preying on moth larvae which consume it. The plant is a hexose-type nectar producer, with glucose being its primary sugar. The Lepidoptera typically seek sucrose-producing flowers. This plant also uses what the researchers described as an "unpleasant odor" to increase pollinator selectivity. Seed dispersal P. brownii seed is, in part, dispersed by rodents, which harvest seeds from the ripe, hanging fruit and store these in small caches up to 20 m away. In Washoe County, Nevada, the yellow-pine chipmunk, deer mouse, and the Great Basin pocket mouse have been observed to do this. The seeds, however, are not considered to be a choice food item, compared to pine kernels, which contain much more fat and protein. Abandoned seeds will germinate early in the next year, following the winter stratification, which breaks their dormancy. Cultivation Brown's