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
