Frasera speciosa (Gentianaceae)
Frasera speciosa is the largest Gentian found in the Rocky Mountains. It most frequently appears as a rosette of smooth leaves, but may produce a flowering stalk that can be up to nine feet tall at lower elevations, but only about 40 cm in the alpine tundra. This plant produces an abundance of purple-speckled white flowers.
Distribution and Habitat
F. speciosa occurs throughout the western U.S. and northern Mexico, and is found primarily in montane and subalpine meadows. It occurs between 2182-3040 m in the East River valley in the vicinity of RMBL.
F. speciosa is a mast flowering species, with significant flowering occurring every 2-7 years in response to an environmental cue (above-average summer precipitation, four years earlier). Mast flowering is thought to be a strategy for avoiding seed predators, but may also benefit pollination.
F. speciosa is a monocarpic perennial, it grows for 22-80 years, flowers once and then dies. The flower stalk is detectable for about three years before it erupts in a tall stalk. A very wet summer (July and August) four years before may be the cue for flowering. It is pollinated primarily by Bombus spp. and solitary bees, but is also visited by a wide range of Hymenoptera, Diptera and Lepidoptera. Its ovaries are frequently attacked by tortricid moths, which eat the ovules and pupate in the ovary walls. Deer eat a lot of fruits, sometimes flowers, but not non-flowering plants. Herbivorous insects have also been known to cause damage to the plants ovaries as described above. F. speciosa co-exists but also competes with a number of other wildflowers including Lipinus, Aquilegia, Potentilla, and Hydrophyllum.
Status and Conservation
There are no known conservation implications or threats of survival for this species.
Beattie, J., D. E. Breedlove, and P. R. Ehrlich. 1973. The Ecology of the Pollinators and Predator of Frasera speciosa. Ecology 54 (1): 81-91.
Card, H. H. 1990. A revision of Genus Frasera. Annals of the Missouri Botanical Garden 18 (2): 245-285.
Inouye, D.W. 1986. Long-term preformation of leaves and inflorescences by a long-lived perennial monocarp, Frasera speciosa (Gentianaceae) Am. J. Bot. 77:11 1535-1540
Taylor, O.R., and D.W. Inouye. 1985. Synchrony and periodicity of flowering in Frasera speciosa (Gentianaceae) Ecology 66:2 521-527
Many thanks to Elissa Hoitt and Dr. Pat Magee of Western State College for this submission, and to Diana Cosand of Chaffey College and Dr. David Inouye of the University of Maryland for reviews and additions.