LIVING SEROTINOUS CONES IN CUPRESSUS SEMPERVIRENS

Cupressus sempervirens L. bears both serotinous and nonserotinous cone s. Serotinous cones are alive and can live for at least 20 yr. The sea ling of cones is regulated by the water status of the scales, and cone s open when they lose water, unlike those of pines, which open followi ng the melting of resin. Serotinous cones even open at 0 degrees C whe n desiccated. Selection favoring cone serotiny in C. sempervirens prob ably resulted not only from fires but also from some other factors cau sing desiccation. The living serotinous cones account for a gradual an d delayed seed dispersal, an advantage over fire-dependent cone seroti ny because it results in intensified seed dispersal after several type s of catastrophes. I show that there is a special type of cone serotin y in C. sempevirens and discuss the possible evolutionary consequences of this strategy.