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 invasive alien species (IAS) provides insight for their management. The reproductive traits of IAS help us 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, South Africa, and North America. Materials and methods – Two populations of A. fistulosus in the Chihuahuan Desert were monitored for reproductive phenology. Floral visitors and their behaviour were described, and we assessed the breeding system through floral morphological characters and the mating system in controlled pollination experiments. Key results – Reproductive phenology showed continuous reproduction throughout the year. Floral morphology suggested a facultative autogamous breeding system, but the mating system was mixed with autonomous selfing. Flowers lasted 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 diverse pollinators, and the autonomous self-pollination implies that a single plant has the potential to develop a new population, which makes the control of this IAS a global challenge.