/ Evidence for a Species-Level Distinction of Two Co-occurring Asters: Aster Puniceus L. And Aster Firmus Nees
ï~~1999 THE MICHIGAN BOTANIST 23 1999 THE MICHIGAN BOTANIST 23 Three lowermost branches segment FIGURE 2. Diagram of various characters used to evaluate the two asters from collected specimens. Rhizome lengths were measured in centimeters and mean BRC was calculated by comparing the portions of the capitulescence branches which were flowering and non-flowering (see text for detailed description). Length to previous Length to next year's shoot year's shoot Calculations were done with Microsoft Excel 5.0. The graphs and table were generated using Cricket Graph 1.3 and Microsoft Excel 5.0. RESULTS The specimens we collected from coexisting populations exhibited several distinct morphological traits. Figures 1 and 3 illustrate that Aster puniceus consistently emerges from a short caudex, while A. firmus annually spreads by extended rhizomes. Figure 4 graphically illustrates differences between the taxa using the variables maximum length to next year's shoot, mean BRC, and number of leaf midvein hairs (there are fewer specimens represented in the graphs than the total number collected because we only graphed those specimens that clearly illustrated all the characters analyzed in the graphs). Underground distance to the following year's shoot was always greater in A. firmus (X = 29.0 cm, sd = 26.6) than in A. puniceus (x = 1.8 cm, sd = 1.3). Aster puniceus was found
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