Table 4.

(a) Physical appearance and SEM images of (b) stomata, (c) cross sections at 500× and (d) cross sections at 1,000× of Azolla filiculoides and Lemna minor at the beginning (Day 0) and end (Day 7) of exposure to 1.00 mg Cu/L.

	Azolla filiculoides		Lemna minor
	Day 0	Day 7	Day 0	Day 7
(a)
(b)
(c)
(d)