Ceratophyllum demersum
hornwort
- Position: full sun to partial shade
- Depth of water: 60-90cm
- Rate of growth: average
- Ultimate spread: indefinite
- Height above surface: 0cm (submerged)
- Hardiness: fully hardy
One of the most popular oxygenating plants, not not only looks attractive, but will help keep your pond free of algae. It has virtually no roots (if any), but its stems are covered in delicate-looking needle-like foliage, which absorbs carbon dioxide. They do die back in winter, but are fully hardy, so come back again each spring.
To increase numbers, break off small sections of stem and pop them back in the water.