Table 1.

Plant growth and development of secondary aerenchyma and lenticels after approx. 14 d flooding: the area of stele (vascular cylinder), secondary aerenchyma and stem in cross-sections of stems at the water surface

Shoot dry weight (g)	0·29 ± 0·03
Root dry weight (g)	0·15 ± 0·01
Stele area (mm2)	2·91 ± 0·15
Secondary aerenchyma area (mm2)	8·37 ± 1·45
Stem area (mm2)	12·7 ± 1·48
Percentage of aerenchyma area in stems (%)	63·8 ± 4·74
Lenticel height at stems above water surface (mm)	6·60 ± 0·51

Aerenchyma area indicates the area not of gas spaces but of aerenchymatous tissues in cross-sections. Percentage of aerenchyma area indicates not porosity but the percentage of stem area occupied by aerenchymatous tissue area in cross-sections.

Digital images of stem cross-sections were photographed using a microscope and analysed with ImageJ 1·38x software (National Institutes of Health, USA) to measure each tissue area.

Values are the mean (±s.e.) of five plants.