Reproductive biology of Petrocoptis crassifolia Rouy (Caryophyllaceae), a chasmophilous endemic plant of the Central Pyrenes

Abstract

[EN] The reproductice biology of Petrocoptis crassifolia Rouy (Caryophyllaceae), an endemic plant of the Central Pyrenees (Spain), was studied. Its nectariferous flowers show an ultraviolet pattern in the corolla and an incipient zygomorphism in the arrangement of petals and stamens. P. crassifolia may produce seeds by autogamy but in smaller numbers than when it is pollinated by insects (mainly Hymenoptera). The fruit-set ranges between 43-80%, depending on the years and populations studied. Fruits develop towards the rock face, and seeds exhibit myxospermy; both these traits are adaptations that facilitate the deposition ofseeds in rocky substrata. Survival of the seedlings in rocky fissures at the end of the first year is 10%. Reproductive traits suggest that this species is well adapted to its habitat, and that it is not endangered. Its rarity seems to be associated mainly with a lack of dispersal mechanisms for colonizing suitable but remote habitats.