Growth forms of biennial and pluriennial vascular plants in central Europe

The growth forms of bi- and pluriennial central European plant species were analyzed and summarized systematically by means of a dichotomous key. Ten growth forms are distinguished according to vegetative morphological characters of the plants: holoparasitic erosulate, (simple) erosulate, floating semirosette, succulent semirosette, tufted semirosette, (simple) semirosette, storage root semirosette, tuber semirosette, storage root rosette, and (simple) rosette bi- or pluriennial plants. Only very few species are strictly biennial or pluriennial. Each individual plant can be assigned to only one growth form system according to the life span (the system of bi-and pluriennials in the present case). However, several species include individuals that behave as annuals as well as biennials/pluriennials and/or periennials. The term "hapaxanthic" is discussed concerning to its reference level in relation to the plant organism. Three types of hapaxanthy can be distinguished in this context: Genet hapaxanthy with and without vegetative reproduction and ramet hapaxanthy.