Delphinium barbeyi, or tall larkspur, flowering in a year with no frost damage. Photographed (by David Inouye) in front of Gothic Mountain, at the Rocky Mountain Biological Laboratory. Altitude about 9,500 ft (2,900m).
A female broad-tailed hummingbird (Selasphorus platycercus) in Colorado visiting tall larkspur (Delphinium barbeyi). The hummingbirds migrate north from Mexico each spring. Larkspurs serve as an important food source for them and for bumble bees. But larkspurs are also susceptible to frost, impacting the species that feed on them.
Buds of Delphinium barbeyi (tall larkspur, Ranunculaceae) killed by a late season frost. In those years, the larkspur suffers reproductive failure, affecting animal species that rely on them for food.
The glacier lily (Erythronium grandiflorum) is one of the earliest wildflowers to bloom after snowmelt in the Rocky Mountains. Its ovaries and seeds are sensitive to late-season frosts. But because the species is a perennial, it can survive occasional years of reproductive failure by blooming the following year. By avoiding the cost of producing the relatively large fruit and seeds in one year,...
A queen bumble bee (Bombus bifarius) foraging for nectar on a flower of Erythronium grandiflorum (glacier lily). This flower has frost-sensitive ovaries. Bumble bee queens and hummingbirds are common pollinators of Erythronium grandiflorum flowers.