Subclass Bryidae, true mosses ( Bryidae )
Order Hypnales ( Hypnales )
Family Hypnaceae ( Hypnaceae )
Genus Vesicularia — Vesicularia.
Christmas Moss — Vesicularia montagnei. “Christmas Moss”.
Brazil. Deciduous aquatic mosses inhabiting springs in fast-flowing rivers with clean, transparent, oxygen-rich water. Leaves consist of a central stem and lateral leaf branches of various lengths, the appearance of which resembles a tiny triangular fir tree. Attached to the substrate, height 1-3 cm.
Leaves are almost round or oval with a short and sharp tip. Leaf cells are wide and short with thin walls. Both veins are barely noticeable. Under submerged conditions, this species can form long triangular shoots. More or less pinnate offshoots are also typical for this moss. This moss is more demanding and grows slower than Vesicularia dubyana. Japanese aquarists were the first to use this unusual moss.
If Christmas Moss is attached to a piece of driftwood or a stone, it grows in the shape of a fir tree (hence its common name). If allowed to grow freely floating, it will generally have a less organized appearance and its triangular structure will be much less pronounced. Due to its branched structure, it forms dense, bright green, pinnate irregularly growing shoots, which distinguishes this moss from the usual Java moss; it is sometimes called the “Christmas tree moss”.
Its formed shoots hang down and overlap each other like spruce branches. Avoid tying it to branching driftwood. It crawls well over rocks, creeping into crevices, and other surfaces. Many hobbyists cultivate Vesicularia montagnei by “building” entire walls out of it, which look very decorative in an aquarium.
It is used in aquarium aquascaping by covering stones and driftwood, filling gaps in planting, or creating living moss walls. To create a moss wall, it is placed between two pieces of net and this structure is secured to the aquarium wall. The moss, growing through the net, covers it, creating a beautiful wall. As a green covering for the bottom of the aquarium, this moss is not suitable, as it gets covered with silt, algae begin to grow on it, and the moss dies.
The plant should be attached to stones or wood; in order to maintain its attractive form, it needs to be regularly trimmed. Gradually it becomes dirtier, accumulating debris; algae eaters and shrimp will help combat this. Shrimp and fish fry use it as a shelter; it is also an excellent source of food for them, as infusoria live in its thickets.
In low light, growth slows down and tends to fall apart, but if the light is good, it forms cushion layers several centimeters high, layer by layer, which is very beautiful. It must be remembered that all the moss located at the bottom, under the upper branches, is rotten; only the upper branches are suitable for replanting, and there will be few of them. Therefore, the old lower part must be periodically removed.
More demanding regarding lighting level (0.5 W/L), as well as CO2 and liquid fertilizers. Under weaker lighting, it grows less densely and often has a less organized structure. It can be grown in an aquarium with almost any lighting and water composition. However, it prefers medium-hard water with a temperature of 24-28°C and a neutral or slightly alkaline reaction. Growth rate is very slow. Maintenance conditions are difficult. It is best to buy this moss in trusted stores where, under good maintenance conditions, its structure is clearly distinguishable.
Identification: Christmas Moss — Vesicularia montagnei. “Christmas Moss”.
Weeping Moss — Vesicularia ferriei. “Weeping Moss”.
China. Grows up to 3 cm in height and up to 5 cm in width, featuring bright green drooping shoots reminiscent of weeping willow branches. This is one of the few aquarium plants whose branches actually hang downward. In leaf shape and its oblong, wide cells, this moss resembles Vesicularia montagnei, however, the leaves of the former are half the size and do not taper toward the end as sharply.
It tolerates very low lighting levels, but can also grow in well-lit aquariums if optimal levels of carbon and other elements are maintained in the water. If nutrient levels in the water are unbalanced, algae can appear on the moss, capable of choking it. Supplying CO2 to the aquarium stimulates the moss to active growth and improves its appearance. The presence of floating debris in the water negatively affects the development of the delicate moss; good filtration in the aquarium is very important for it.
It looks beautiful when attached to driftwood and stones; it is best to secure it with fishing line or nylon thread, as it does not hold very firmly on them by itself. But be patient, as the moss takes some time to adapt. And only after getting used to the new conditions and gaining strength does the moss begin to grow intensively. Moss adaptation can take up to several weeks. Weeping moss attached to driftwood makes it look very much like a real willow. It grows fast and needs frequent trimming with scissors to maintain an attractive shape. But it looks best when allowed to grow unpruned, creating a very natural draping effect in the aquarium.
Old branches tend to rot and die off. Optimal conditions for keeping the moss: medium-hard water with pH 5.5-7.5, KH 4-15°, temperature 20-25°C. It also withstands higher temperatures (up to 32°C) well without losing its unique appearance. However, the moss branches may turn yellow in the process.
Identification: Weeping Moss — Vesicularia ferriei. “Weeping Moss”.
Erect Moss — Vesicularia reticulata. “Erect Moss”.
Under submerged conditions, this species requires powerful lighting. The English name of the plant comes from the fact that underwater, the shoots assume a vertical position. Leaves are egg-shaped or lanceolate-ovate with a long tip. Leaf cells are oblong and wide, much longer than in V. montagnei, but not as long and narrow as in Taxiphyllum barbieri. Like V. montagnei, Vesicularia reticulata is a terrestrial moss widespread in tropical Asia that prefers to settle in humid biotopes. This moss cannot be confused with any other species: the shoots of Vesicularia reticulata always point upward. This moss is not suitable for the foreground as it grows vertically upward.
Identification: Erect Moss — Vesicularia reticulata. “Erect Moss”.
Taxiphyllum alternans, Taxiphyllum barbieri, Flame Moss, Spiky Moss, Peacock Moss.
Vesicularia dubyana, Singapore Moss, Java Moss. 
