3. Estimation of horizontal rhizome elongation and rhizome plastochrone interval for monomeristematic
species:
Collect rhizome fragments as outlined above; measure the length and dry weight of the
fragments and the total number of rhizome segments in each fragment, and calculate, using
either regression analysis or simple ratios, the mean (± SE) length and weight per rhizome
segment. Calculate the rhizome elongation rate (cm day-1) as the ratio between the
rhizome length per segment (node plus internode) and the plastochrone interval, which is
the same for rhizome nodes and leaves for these species.