Ecotypic differentiation and phenotypic plasticity in Saxifraga hirculus populations in central and northern Sweden

The perennial herbaceous mire plant Saxifraga hirculus was grown for two years in a greenhouse under two nutrient regimes. Based on metric characters, primarily those associated with the potential for lateral spread, I found ecotypic differentiation both between plants originating from three adjoining but different habitats on one mire and between plants from three widely separated habitats. The fact that seeds from the different habitats germinated in different proportions after a first and second period of stratification. suggests that there is a habitat‐specific, innate seeddormancy. Also the degree of phenotypic plasticity differed among the plants, viz. plants from the least fertile habitats exhibited the largest plasticity.