Tradeoffs among growth, asexual and sexual reproduction have not been extensively documented despite the vast number of organisms that can reproduce through asexual and sexual methods. This experiment characterizes life-history variation among genotypes and tests for tradeoffs among life-history traits in the dioecious bryophyte Marchantia inflexa. Marchantia inflexa can reproduce asexually from gemmae produced in cupules or sexually through spores. Genotypes were collected from populations in Trinidad that were classified as either Sex Expressing (SE) or Non Sex-Expressing (NSE) based upon the presence or absence of sex expression in the population at the time of collection. Sixty-four genotypes, sixteen males and sixteen females from both SE and NSE populations were grown in a greenhouse in either high or low light conditions. The plants were censused thrice weekly and the dates of first asexual and sexual reproduction were recorded. Plant size and the number of cupules and sex structures were quantified bi-weekly. MANOVA's were used to assess the variation for two growth, asexual and sexual characters (i.e. 6 parameters) and repeated measure analysis was used to compare the amount and pattern of cupule and sexual production. Genotype identity was nested within sex for all analyses. The MANOVA detected a significant genotype (Wilk's Lambda=0.1 F=1.3 p < 0.05) and sex (Wilk's Lambda=0.32 F=3.6 p < 0.0001) effect on M. inflexa life-histories. Genotypes displayed clonal heritability estimates between 0.74 and 0.017. The repeated measures analysis detected significant interactions between time and sex (Wilk's Lambda=0.9 F=1.6 p< 0.01), genotype (Wilk's Lambda=0.2 F=1.3 p< 0.0001) and the combination of light and sex (Wilk's Lambda=0.9 F=1.3 p < 0.05) on cupule production. Pearson's correlations did not find evidence of negative tradeoffs as early cup production was positively correlated with early sex expression (r =0.21 p< 0.01) and high growth rates (r = 0.17 p< 0.01).

Key words: Marchantia inflexa, bryophyte, clonal heritability, cost of reproduction, life-history tradeoffs