Star Duckweed
Lemna trisulca
Family: Lemnaceae
What it is like
Lemna trisulca is a PERENNIAL. See above for USDA hardiness. It is hardy to UK zone 4 and is not frost tender. It is in flower from May to July. The species is monoecious (individual flowers are either male or female, but both sexes can be found on the same plant). It is noted for attracting wildlife. Suitable pH: neutral and basic (mildly alkaline) soils. It cannot grow in the shade. It can grow in water.
Height (m): 0
Where it is found
Ponds and ditches in all parts of Britain except north Devon and east Cornwall. Mesotrophic, quiet waters rich in calcium, in cool-temperate regions.
Europe, including Britain, from Scandanavia south and east to N. Africa, Asia, N. America, Australia
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 0
Medicine
Rating: 1
A poultice of the wetted plant, combined with another plant, has been used in the treatment of swellings.
Other
Rating:
Attracts Wildlife: Plants noted for attracting wildlife
How it is grown
Requires a sunny position in still water that is rich in nitrates and lime. Duckweed can be a troublesome pond weed though it is easily controlled by simply scooping it out. This scooped out material makes an excellent addition to the compost heap. The growing plant is a good food source for fish and birds, as well as providing cover for creatures in the pond. This species is very suitable for use in cold water aquaria though, like all members of the genus, it can harbour fish parasites. The plant over-winters in temperate areas by means of resting buds which sink to the bottom of the pond in the late autumn and rise again in the spring.
Propagating it: Seed - we have no information on this species but, since it spreads so rapidly by division, it really needs no extra help once it is in a pond.
Best place to grow: Pond;
Habit: Perennial
Hardiness: 4-8
Growth:
Soil:
Shade: No shade
Moisture: Water