Comparative fecundity of morphs in a mixed monoclinous-andromonoecious population ofWurmbea dioica subsp.alba (Liliaceae) in Western Australia

Abstract

A population ofWurmbea dioica subsp.alba in Western Australia contained monoclinous and andromonoecious individuals in roughly equal proportions. The average number of flowers per inflorescence for the former was 2.6 and for the latter 2.9, with its terminal flower staminate. Ovule number and seed production per perfect flower of both morphs decreased progressively from lower to upper flowers in the inflorescence. Two-flowered monoclinous individuals had a greater percentage of ovules maturing to seed than did threeflowered ones, but seed production of the latter exceeded that of the former. No differences in percent seed set or in seed production were noted for similar individuals of andromonoecious individuals. Although monoclinous and andromonoecious plants apparently contributed equally to the pollen pool, seed production of the former exceeded that of the latter. Thus, the energetic costs of monocliny exceed those of andromonoecy in this population.