Life cycles and biomass allocation in seed- and ramet-derived plants of Cryptotaenia canadensis (Apiaceae), a monocarpic species of eastern North America

Abstract

Life cycles, survivorship, and biomass allocation for seed- and ramet-derived plants of Cryptotaenia canadensis (L.) DC. were studied to determine if variation existed between plant derivations, and how these attributes contribute to persistence of the species within a temperate forest habitat. Seed-derived plants behaved as biennials, reproducing both sexually and asexually in the second growing season. Ramet-derived plants reproduced sexually and asexually annually. Annual survivorship was greater for seed-derived juveniles; however, fewer seed-derived plants flowered than did ramet-derived plants. Biomass allocation for plants harvested at four growth stages over two complete life cycles was significantly different between plant derivations during vegetative growth stages. During reproductive growth stages, biomass allocation did not differ between ramet- and seed-derived plants harvested in the same year. Regressions showed a strong correlation between sexual reproductive mass and vegetative mass for both plant derivations, with no significant difference between slopes or intercepts. Ramet mass was less dependent on plant size, and differences between slopes and intercepts were not significant. Regressions of sexual versus asexual reproductive mass varied with year and cohort. Equivalent reproductive output in conjunction with temporal differences in life cycle phenologies between plant derivations optimize this species' ability to persist in its natural habitat.Key words: allometry, Apiaceae, biomass allocation, Cryptotaenia canadensis, monocarpic.