Hornwort, Coon's tail
Ceratophyllum demersum
Family: Ceratophyllaceae
What it is like
Ceratophyllum demersum is a PERENNIAL growing to 1 m (3ft 3in) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 8. It is in flower from July to September. The species is monoecious (individual flowers are either male or female, but both sexes can be found on the same plant) and is pollinated by Water. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers wet soil and can grow in water.
Height (m): 1
Where it is found
Ponds and ditches.
Most of Europe, including Britain, but absent from the Arctic.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 1
Leaves. No further details are given.
Medicine
Rating: 1
The plant is a cooling antiperiodic. It is useful in the treatment of biliousness and scorpion stings.
Antiperiodic: Counteracts recurring illnesses such as malaria.
Stings: Used in the treatment of stings and insect bites.
Other
Rating:
How it is grown
Prefers a sandy medium rich in decaying organic matter in full sun, but it tolerates shade better than most submerged aquatic plants. A good pond oxygenator, it usually grows submerged in the water but is sometimes found floating on the surface. This species belongs to one of only two known dicot genera where pollination taks place under water. The anthers of male flowers break off the plant and float to the surface where they release their pollen grains. These then sink under the water to fertilize the female flowers. This species, however, more commonly reproduces asexually. In some parts of the world bilharzia-carrying snails and malaria-carrying mosquito larvae shelter in the leaves of plants of this genus. The plants can also grow so vigorously as to choke waterways, though they also provide good shelter for young fish. The plant is very brittle.
Propagating it: Seed - we have no details on this species but would suggest sowing the seed as soon as it is ripe in early autumn in a greenhouse with the pot immersed in water. It is likely that the seed will quickly lose viability if allowed to dry out so if it is stored it should be kept cool in a container of water and then be sown in late winter. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in a tray of water in the greenhouse for at least their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts. Cuttings in the growing season root easily. Plants propagate themselves naturally when scaly young shoots or winter buds separate from the main plant.
Best place to grow: Pond; Bog Garden;
Habit: Perennial
Hardiness: 7-10
Growth: Fast
Soil: Light (sandy), medium, heavy (clay)
Shade: Semi-shade, no shade
Moisture: Wet, water