Eriocaulon sp. "Japan Needle Leaf"

This remarkable grass-like plant was brought onto the market in Asia under the name Eriocaulon sp. "Japan", however, in the hobby, several different Eriocaulon variants are known under that name. Its species identity is still unclear. It is certainly not native to Japan and resembles certain Eriocaulon species that occur in rocky beds of fast-flowing rivers in India. Its submerged leaves are flexible, dark green and smooth. They grow to a length of approx. 30-40 cm with a width of only 1.5 mm. The leaves are distichous, which means that they grow in two rows on the rhizome - quite uncommon for an Eriocaulon. The creeping, short, hard rhizome branches readily, forming a large, dense grass-like tuft with time. Sometimes, young leaves get stuck when sprouting and become wrinkled. They can be removed and are normally followed by straight leaves.
Interestingly, this Eriocaulon attaches itself to solid material such as rock or wood. Therefore it seems likely that it occurs naturally on rock or in gravel in flowing waters. Occasionally inflorescences appear that remain shorter than the leaves. When they are able to grow out of shallow water, its flowerheads open, exposing many tiny greyish white flowers. When the heads remain submerged, they develop adventitious plantlets.

Quite contrary to other Eriocaulons, "Japan Needle Leaf" grows in very well in our tanks, not only with soft water rich in CO₂ and acidic substrate (Aquasoil), but also in medium hard water, at a temperature of approx. 21-26 °C. This Eriocaulon is apparently also quite frugal when it comes to fertilisation. Macro- and micronutrient supply via the water column is sufficient, a nutrient-rich substrate is not necessary. The plant can be propagated by dividing the branched rhizome or by the adventitious plantlets on the submerged inflorescences.

With its elegant grasslike leaves, Eriocaulon sp. "Japan Needle Leaf" is an alternative to other narrow-leaved plants like Vallisneria gracilis ("V. nana") or Helanthium bolivianum "Angustifolius". Unlike these, it does not form runners and is thus easy to control in an aquascape. It also provides interesting possibilities for aquascaping when it is used as an unusual epiphyte, e.g. on or between stones in stream biotope tanks. If the Eriocaulon grows near the surface, you can expect to see its interesting-looking head-like inflorescences above the water.