Pollination ecology and floral function of Brown’s peony (Paeonia brownii) in the Blue Mountains of northeastern Oregon

By Peter Bernhardt, Retha Meier, Nan Vance

A pendant flower of Brown’s peony (Paeonia brownii) with a vespine wasp seeking nectar. Photograph Nan Vance

Brown’s peony (Paeonia brownii) is one of only two peony species that are native to the western hemisphere. The two species are found in western North America growing almost exclusively in the wild. The Brown’s peony grows north of the California peony and at higher elevations. We wanted to find out more about the flowers and pollinators that visited the flowers of this wild cousin of the ornamental peony. At a location that encompassed a prairie habitat in the Blue Mountains of Northwestern Oregon, we examined the flower’s pollen for sterility and for its interaction with the carpel (whether it was self-compatible with its own pollen or strictly a cross-pollinated flower).  We investigated the flower’s insect visitors and determined which visitors were potential pollinators. We also measured the nectar quantitatively and qualitatively. 

Read the whole summary in: English.
Read the scientific publication in JPE .

Do native bees have the potential to promote interspecific pollination in introduced Impatiens species?

By Paola Ugoletti, Darren Reidy, Michael B. Jones and Jane C. Stout

Impatiens glandulifera (the larger species) and I. balfourii.

The anthropogenic movement of species can bring together species which would be naturally separated by geographical barriers. One potential consequence is cross-fertilization and hybridisation between closely related species, which could result in novel, more versatile offspring, which could become more invasive than the parents. In order for hybridisation to occur between non-native plant species, they must flower at the same time, and their reproductive systems must allow interspecific (cross-species) pollen transfer. In addition, animal-pollinated species require appropriate flower visitors who include both species in their diet and who switch between them during a single foraging bout, thus mediating interspecific pollen transfer. Moreover, interspecific pollen must be able to germinate on the stigma and grow a pollen tube through the style, fertilize the ovule and form a functional seed, and the seed must be able to germinate and grow into a new plant.

Read the whole summary: in English
Read the scientific publication in JPE.