7. Beitrag zur Wuchsform und Biologie der Gefäßpflanzen des hercynischen Raumes: Bupleurum virgatum Cav. (B. gerardii auct.; Apiaceae)

Abstract

Herrmann, N.: Contributions to the growth form and biology of Hercynian vascular plants: Bupleurum virgatum Cav. (B. gerardii auct.; Apiaceae). – Hercynia N.F. 39 (2006): 89–119.Bupleurum virgatum Cav. is a wintergreen plant species, which occurs in Central Europe exclusively in the north-eastern Harz-mountains in the valley of the river Selke. The karyotype of the diploid species (2n = 16) is described for the first time. B. virgatum has linear, bifacial, amphistomatic leaves, which are arranged distichously at the base of the stem. Plants reach a height of up to 75 cm. The side shoots are branched to the 5th order and end in double umbles composed of 3–8 umbellules, that each consist of 4–8 flowers with yellow petals. The bisexual flowers are characterized by proterandry and self-pollination. From each fertile flower emerge two diaspores. The dispersal type is autochory. The diaspores germinate completely in autumn, the majority of seedlings decline during winter. Indicator values are proposed for the first time. In observations over 4 years at the site “Alter Falkenstein” in the valley of the river Selke a regressive population size was detected. The reason for this development was habitat destruction due to leisure activities by tourists. New aspects from the life history and biology of the species indicate a synanthropic origin of B. virgatum in Central Europe.