LONG-TERM PREFORMATION OF LEAVES AND INFLORESCENCES BY A LONG-LIVED PERENNIAL MONOCARP,FRASERA SPECIOSA (GENTIANACEAE)

In Frasera speciosa, a long-lived monocarpic gentian from the Colorado Rocky Mountains, leaves are preformed two to three yr in advance of their appearance above ground. Initiation of a flower stalk may begin as long as three yr before it becomes fully developed during a plant's final year. Whorls of preformed leaves are initiated continuously during the growing season, but they are enlarged only once a yr, when the basal rosette emerges above ground. This pattern of development allows plants to make maximal use of the growing season. The prolonged development may be necessary for the production of an elaborate and massive flower stalk by a slow-growing plant in a habitat with a short growing season.