TankBud

Star duckweed

Lemna trisulca

Also known as Ivy duckweed, Ivy-leaved duckweed, Narrow-leaf duckweed, Star duckmeat

FreshwaterFloatingdivisionfragmentation

Star duckweed (Lemna trisulca)
Christian Fischer · CC BY-SA 3.0

Care at a glance

Light
Low light
CO2
No CO₂ needed
Temperature
50–79°F
10–26°C
Max height
0.4 in
1 cm
Growth rate
Medium
Placement
Floating
Type
Floating
pH
6.0–8.0
Hardness
2–18 dGH
Spread
7.9 in (20 cm)
Nutrient uptake
Water column
Growth region
Submersed or emersed
Difficulty
Easy
Family
Araceae
Origin
A cool water duckweed of temperate ponds and slow streams across the Northern Hemisphere, drifting just under the surface rather than on top of it.

Overview

Let it drift under the surface in low to moderate light with no CO2 required, and it will slowly build up into cushions. It is far less aggressive than common duckweed, so it will not choke the surface, and it tolerates cool temperatures well. Thin it if it gets thick enough to shade plants beneath.

In the wild

Unlike the duckweeds that coat the surface, star duckweed grows as translucent, toothed fronds joined in branching, ivy like chains that hang just below the water line. The chains tangle into loose cushions that drift midwater and only rise to the top to flower. This gives shrimp and fry a soft, sheltering thicket without blanketing the surface.

Good to know

Star duckweed is one of the few duckweeds that grows submerged, with fronds staying connected in crosswise chains rather than floating singly. It sits in the arum family, the same broad group as anubias and philodendron.

Did you know

Because it floats below the water rather than on top, it is much easier to live with than surface duckweed and rarely takes over a tank.

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