Seed Production and Seedling Establishment in the Mayapple, Podophyllum peltatum L.

Abstract

Mayapple (Podophyllum peltatum L), a perennial clonai herb, produces flowering and nonflowering stems. Stem densities per clone are fairly constant from year to year, but fruit and seed production is variable, both among clones and among years. Fruit production is positively correlated with flowering stem density per clone. Seven age-specific mortalities are recognized from flowering to seedling establishment: flower abortion, improper pollination, immature fruit loss, failure of fruits and seeds to be removed from clone area, seed pr?dation, failure of seed germination and seedling competition. Improper pollination is responsible for the largest loss of potential seeds; failure of seeds to be removed from the clonai area is the second most important mortality factor. Eastern box turtles (Terrapene carolina) are the only seed dispersal agents so far identified. Turtle-ingested seeds germinate faster and have a higher probability of success than noningested seeds. The survivorship curve for turtle-ingested seeds is Type II. The negative exponential model for seedling mortality best describes the mayapple and predicts a reduction of the initial seed crop to one plant by the 5th year.