Growth as a function of height: Echinocactus horizonthalonius
Most plants begin flowering at 3-4 cm in height. Onset of flowering does not appear to affect growth rate (as it does with saguaros).
Two charts are shown: growth by height class, and growth as a scatter plot. Patterns are difficult to detect. It may be that plants grow fastest in the middle height classes.
Average growth in height per year is 0.4 cm.
The interval of measurements varies from individual to individual. The largest interval is 9 years (1995-2004), and the smallest, 1 year. Shown are the average height (averaged between all height measurements), and average growth per year (ditto).
The error bars are standard errors of the mean.
Below: the same scatter plot, with the three outliers included:
