Streamside Leptodictyum moss

Description

Leptodictyum riparium is a type of moss that grows upright with "stringy" foliage. However, native populations from Germany have a different appearance under the same conditions, forming horizontal shoots with dense, flat foliage. This growth habit matches descriptions in taxonomic literature better than the popular "stringy moss", which is actually Drepanocladus aduncus. Leptodictyum riparium is widely distributed and one of the most common aquatic mosses in Central Europe. It grows on edges and in shallow zones of stagnant or slow-flowing waterbodies with nutrient-rich water, tolerating pollution well. Its emersed form creeps on hard substrates like rocks, tree roots, and river embankments. The submersed form of this moss grows floating shoots that are rarely branched or moderately branched. Leptodictyum riparium is highly variable and its appearance depends on the conditions it grows in. In nature, it is often confused with Fontinalis antipyretica ("willow moss"), but can be distinguished by the presence of a midrib on its leaves. The leaves of L. riparium grow in a flat habit and have a pronounced midrib that does not reach the leaf tip. The leaf cells are very long and narrow, 6 to 20 times longer than wide. This moss is suitable for coldwater tanks and can also thrive in moderately warm tropical aquaria. It can be attached to rocks or driftwood with its rootlets but often forms long strands floating in the water. Under intense light, L. riparium ramifies better and may produce many small oxygen bubbles on its leaves. It can be kept on the edge and in shallow-water zones of garden ponds with partially shaded conditions and nutrient-rich water.