Key ecological determinants of the reproductive success and conservation strategy of Delphinium pentagynum subsp. formenteranum (Ranunculaceae), an endangered endemic species of the western Mediterranean Basin (Balearic Islands)

Abstract Delphinium pentagynum subsp. formenteranum is an endemic species restricted to the island of Formentera (Balearic Islands), where it considered endangered species. Ecological traits such as pollination and pollinator-plant interaction, seed germination are key processes required for conservation efforts but remain poorly characterized. Floral were evaluated analysing total alkaloid content vegetative plant, floral, nectar pollen, volatile emitted by flowers. Flowering phenology was assessed in field three different years (1998, 2008, 2018) under cultivated conditions D. cohabiting Germination trials conducted both at constant alternate temperatures, lots conserved room temperature germinated across 7 assess viability with age. Micromorphological scanning electron microscopy. Results show intraspecific flowering synchrony occurring May after peak lack odor related volatiles high plant remains unaffected within a broad spectrum temperatures only negatively affected (23ºC). Seed maintains rates first 2 (~ 100%) decreases four-five (40–60%) six (20%), being non-viable seven years. Both phenological displacement flowers support specificity, which almost exclusively Anthophora balearica. ecology dependent mainly on water availability, longevity allows probable transient bank seed.