The identity of Vincetoxicum in Norway

Norwegian Vincetoxicum has previously been referred to V. hirundinaria in standard floras but partly to an aberrant form, called var.fuscatum or ssp. fuscatum . Our comparative morphological and allozymatic data unambiguously relate present day Norwegian Vincetoxicum populations to V. rossicum as circumscribed in standard European floras, i. e. with brown corollas, dark purple coronas, and twining stems up to 2 m in height. However, specific status of this taxon is questionable and varietal rank has been suggested, e. g. V. hirundinaria var. rossicum . Present Norwegian occurrences probably represent descendants from introductions by man prior to 1865 (first Norwegian record). The species has established itself as a permanent member of the Norwegian flora and although restricted to relatively small areas in Oslo (Oslo Co.) and Drammen (Buskerud Co.), it shows invasive tendencies at present.     

Aspects of reproduction in Pulsatilla pratensis in Norway

Breeding system and pollinator activity were studied in two Norwegian populations of Pulsatilla pratensis : a small outpost population, on Hovedøya in Oslo, and a large population located centrally within the main area of this species in Norway, on Sandøya in Tjøme, Vestfold. One objective was to assess, if possible, the chance of survival of the outpost population. Pulsatilla pratensis is not completely self incompatible, since artificial selfing produced a small amount of seed. However, spontaneous selfing does not occur. Pollination is accomplished by insects, almost exclusively bumble bees ( Bombus spp.). Nectar thievery resulted when the bumble bee inserted its proboscis from outside the flower in between the tepals (base working). A comparison between the two populations indicates that pollinator scarcity at the time of flowering possibly might constitute a limiting factor for recruitment in the outpost population.