Scientific Name: Ceratophyllum demersum
Common Name: Hornwort
Synonyms: Coontail
Family: Ceratophyllaceae
Origin: n/a
Distribution: Everywhere apart from extrems.
Height: 5-80+ cm
Width: 3-5+ cm
I have strands over 1 meter in length and I'm sure they can grow longer if given the opportunity.
Conditions:

* Water type: Freshwater, on occasion survives brackish.
* Temperature: 5 - 30°C (Survives in ponds which freeze over)
* Light: Any.
* pH: 5.0 - 9.0
* Hardness: Any.
Growth: Very fast in warm, brightly lit conditions. Slow in cold water and low light.
Propagation: Cuttings.
Ease of Keeping: Very easy.
Position: Floating, weighed down, tied down or one end buried in gravel. Rootless plant, so can be stightly hard to find the bottom end there is one at that!
A wonderful plant for fry to hide in and for betta breeding because the pair can always see eachother (so the male keeps his mind on the job) but very hard to get through (so the female or male does not get hurt by their potential mate). Be very careful when collecting it from ponds because it can be home to leaches and dragonfry larvae.