Author: Drinda Jacobson
Common Names: Threestamen waterwort, longstem waterwort, mudwort
Native Distribution: United States and Canada
Aquarium Placement: Foreground
Requirements: CO2, high light, heavy iron supplementation, and macrofertilizer
Elatine triandra is a delightful foreground plant. Its small stem width of ½ to 1 inch, rich bright green color, and ease of growth make it a beautiful choice in any size aquarium. The somewhat elongated and rosette-like leaves at the stem’s end make it a unique foreground plant.
In nature this plant grows along the edges of waterways and, more specifically, in the mud flats of tidal rivers and marshes. Its natural habitat is in the cooler regions, and it reseeds itself for each growing season, making it an annual plant. Relatively rare and hard to find, it can be obtained from fellow hobbyists. The hobbyist should expect an adjustment period for this plant while it acclimates to its new environment. It does not ship well and is not generally available commercially.
E. triandra is a nutrient hog; high light, rich macrofertilizer, heavy iron supplementation, and CO2 are essential. If any one of these is not supplied, the plant will melt and disappear. Even when a rich, nutritious substrate is provided, additional fertilizer must be dosed into the water column.
E. triandra is used exclusively as a foreground plant. It can be used along with other foreground plants of different height and leaf varieties to enhance the overall interest in the foreground. E. triandra grows quickly and will run along the substrate and fill all available space. It will grow over itself if not trimmed, eventually shading the under-layer, causing the whole mass to detach from the substrate. Many aquarists find that the time and work to maintain it is just too much. Others, enjoying its beauty, just continue to replant the lifted lawn, letting it regrow the foreground. Few hobbyists are able to keep this plant over the long term. Once established, the main reasons for loss are shading and detaching from the substrate.
Since E. triandra is a stem plant, propagation is easy. The plant can be cut anywhere along the stem. The trimmings can be shallowly planted or gently weighed down so it touches the substrate where roots will form and take hold. The plant is also known to spread by seed propagation in the submerged state.
Notes: E. triandra is just one of 10 Elatine species, and out of those only three are kept by aquarists: E. americana, E. minima, and E. triandra. It is important to know which species you are getting before purchase because all three have some unique care requirements. Another important point is that it will take a good deal of effort to obtain any of the three species, since they are unavailable commercially and can only be obtained from other hobbyists.