Re: Ceratopteris thalictroides

Aquatic plants are well known for their 'phenotypic plasticity'. That is, they
change their form easily. This can be in response to water chemistry, 
nutrition, water depth, light quality, light intensity, water pressure, 
light duration, temperature etc... As to your specific situation, I dont 
know but have observed similar growth from my Ceratopteris.

Dr. dave