The reproductive traits that contribute to the invasive success of Mediterranean onionweed (Asphodelus fistulosus)

Abstract

Background and aims - Understanding the traits that lead to the invasion potential of alien invasive species (AIS) provides insight for their management. The reproductive traits of AIS help us to understand the mechanisms that allow for their invasive potential, and colonization into new ranges. Asphodelus fistulosus is a native Mediterranean species commonly found invading Australia, South-East Asia and North America. Materials and methods - Two populations in the Chihuahuan Desert of A. fistulosus were followed for reproductive phenology. Floral visitors and their behavior were described, and we assessed the breeding system through floral morphological characters and the mating system in controlled pollination experiments. Key results - Reproductive phenology shows a continuous reproduction throughout the year. Floral morphology suggests a facultative autogamous breeding system, but the mating system is mixed with autonomous selfing. Flowers longevity was one day, with anthesis lasting 11 h. Floral visitors of A. fistulosus consisted of a variety of taxa including species of Coleoptera, Hymenoptera and Lepidoptera, the exotic Apis mellifera being the most frequent visitor. Conclusions - The reproductive traits of A. fistulosus in the invaded range provide the biological potential for further invasion. The continuous production of reproductive structures attracts many pollinators, and the autonomous self- pollination implies that a single plant has the potential to develop new populations, posing the control of this AIS as a global challenge.