dennis

I don't know if this is the right forum but since the question deals with the physiological characteristics of aquatic plants....

Are there any aquatic plants that are poisonous? There are scores of terrestrial plants, and many marine organisms that use chemical warfare as a defense mechanism, what about freshwater aquatic plants? I can't come up with any?

HeyPK

Hygrophila balsamica is said to be very poisonous for fish if it has been grown emersed. Kasselmann recommends that it be soaked for three days before being introduced into the aquarium.

AaronT

Dang...you beat me to it. I have some, but I don't plan on confirming this with my fish.

HeyPK

Bacopa caroliniana has a minty or herbal smell. This in terrestrial plants indicates some kind of repellent action against insects. B. caroliniana doesn't seem to bother any aquarium inhabitants, however. I have never seen anything eat it, however. It might be interesting to try out some B. caroliniana with a Columbian ramshorn snail, which eats most other aquarium plants.

neonfish3

It's funny you mention this subject. I'm doing research now on aquatic plant medicinal value, food value, and folk lore. I want to write an article.

Did you know?

Lobelia cardinalis root- Was used by Cherokee and Iroquois Indians for treating syphilis. Also as an emetic (to induce *****ing) and expectorant.
Polygonum hyrdopiperoids-was used as a cure for everything from toothaches and epilepsy to gangrene and gout. Today it is used in folk medicine as an external astringent, a remedy for diarrhea, and a contraceptive. Also yields a golden yellow dye.
Lysimachia nummularia- for treatment of wounds and sores. The dried and powdered plant was used for the treatment of scurvy and bleeding wounds. Also the plants juice boiled with honey and wine was good for any internal bleeding. And a syrup made from the plant was used for whooping cough.
Water lilies-Nymphaea alba, Nuphar lutea- White water lily has been prescribed as an anaphrodisiac (inhibits sexual drive)lol. Both plants contain tannin and mucilage and have been used as astringents to halt diarrhea and as demulcents to help soothe irritated, sore throats.

Just to name a few.......

Steve T.

WARNING- only for reference and informative purposes. Do not self medicate without doctors care.

plantbrain

I eat Scirpus all the time, the native Americans showed me what part and how to get at it. Quite tasty. Best harvested later in the fall.
Can be cooked or eaten raw, better than heart of palm.

Regards,
Tom Barr

Rusalka

What about plants that are toxic to dogs? I'd like to have a pond this summer but my doggy loves to munch on foliage, and I think emergent leaves will be to interesting to resist. We've been able to dog-proof our terrestrial garden with non toxic plants, and I'd like to be able to do the same for our pond.

Any ideas? I don't mind just having a couple of plants, if that's all I can come up with. So far all I've got is that bacopa monnieri, in it's emergent form, is non-toxic. So I assume it is safe submerged too!

Tex Gal

Be careful about putting aquatic plants outside!!! You should only put native species to your area outside. If you try to put others outside wildlife, winds etc can carry them off to native waterways. We are dealing with overbearing legislation in TX because people have not be careful and have contaminated local streams, ponds, rivers, etc. with exotic plants. People don't realize that these things flower and seeds are spread or birds, frogs etc can spread them.