Re: Bubbles on plants

Most, if not all, aquatic plants possess extensive air channels or 
lacunae which are sometimes called aerenchyma. For those vanishingly few 
who are interested, aerenchyma are either lysigenous or schizogenous in 
origin. Many of these air channels are directly connected to the external 
aquatic environment through structures called hydropoten. The 
hydropoten are generally found at the tips of submerged leaves. Often, the 
bubbles that you see streaming from aquatic plants are being released 
from these hydropoten. This is an indication that the lacunar system is 
pressurized by O2 formed during photosynthesis.

dave h.