Population studies on Anemone nemorosa L. in Britain

• Main Author: Shirreffs, D. A.
• Published: University of Aberdeen 1981
• Subjects: 581.7
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.593427

Anemone nemorosa L. is a common and widespread species over much of Britain, occurring with a wide ecological amplitude. In this study the biology and variability of the species were examined. The nomenclature of the species and its many varieties is clarified, with descriptions of the varieties. Eighty-nine natural populations were sampled and analysed for twenty-seven morphological characters. These data were mainly analysed using a computer-aided Principal Components Analysis. The species was found to be very variable even within one clone and this masked any differences between populations. No pattern could be detected in the total variation which seemed unaffected by geographical, ecological and seasonal factors. The large variability is partly a result of outcrossing and partly due to phenotypic plasticity. Seeds are slow to germinate and are rarely successful in establishing themselves in mature populations. The effective reproduction is therefore by rhizome extension. A computer simulation of rhizome growth is described. Phenotypic plasticity in a vegetatively reproducing plant will confer on it some of the advantages of outbreeding and may allow it to survive if habitat conditions change. The response of A. nemorosa to several environmental factors is described. Soil moisture is thought to be the most significant factor determining the distribution of the species. The effect of felling deciduous woodlands is discussed. Ten populations were analysed cytologically. The chromosome number was always 2n = 30, the most common number recorded by previous authors. Mitosis was regular and meiosis, on the whole, was also regular although occasional irregularities were observed. Fifteen bivalents were observed at meiosis. A. nemorosa is an aneuploid tetraploid and the absence of multivalents at meiosis suggests that it is an allopolyploid species. A preliminary survey of isozymes in four populations found no interpopulation differences.