Figure 1

Plant performance and life-cycle traits of C. stoebe geo-cytotypes. C. stoebe plants were grown from seed in a common greenhouse environment. Plants were measured for leaf length and leaf number while in rosette form, and these values were multiplied to obtain an early indicator of biomass (A). After bolting, stem height (B) of each bolting plant was measured the day the first flower opened and the number of capitula per flowering plant (C) were counted after the stems had senesced. The number of newly formed rosettes after flowering (D), the percent of flowering individuals (E), and the percent mortality after flowering (F) were monitored. Legend; 2× EU, native Eurasian diploid populations; 4× EU, native Eurasian tetraploid populations; 4× US, invasive North American tetraploids. Significant differences in plant traits were determined for geo-cytotypes of interest (EU 2× versus EU 4× and EU 4× versus US 4×) using pair-wise comparisons of LSmeans. Bars represent LSmeans and standard errors. Fisher's LSD was used for pair-wise mean comparisons. Different letters above the columns indicate significant differences (P < 0.05) between pairs of geo-cytotypes.