Figure 1.

A and B, Orientation of the third oldest petiole (third oldest leaf is indicated by arrows) of a 27-d-old R. palustris plant after 0 and 16 h of submergence. C, Hyponastic growth kinetics of the third oldest petiole under water (4 replicate plants; bars represent ses). Lag-phase, 2.1 h (se 0.5 h); end hyponastic growth, 6.4 h (se 0.4 h). D and E, Epidermal cell length along the adaxial (upper; D) and abaxial (lower; E) surface of the petiole, from the base to the apex. Plots are means of 4 replicate plants. The insert shows a transverse section through the petiole, and the boxes in the section indicate the collenchyma strands on which the epidermal cell length was measured. The lines in the insert are explained in Figures 4 and 6. Mean se never exceeded 15% in D and E.