Hydrocotyle Tripartita 


Three part pennywort

Forms creeping or overhanging shoots

Can be used as a carpeting plant or for other uses.
Very popular aquarium plant
AKA: Hydrocotyle "Japan", "Australia" or "Maritima" 



Hydrocotyle sp.'Japan' is the popular name of the plant in different plant forums. It is a variant of Hydrocotyle tripartita from South-East Asia. It is characterised by fast, compact growth and small, intense green leaves on vertical stems.
The plant is carpet-forming (5-10 cm tall) and its compact growth can be promoted by physically pressing the carpet with your hand when maintaining your aquarium (mechanical retardation). Carpet formation and compact growth do best in good light. 

This small delicate water pennywort is especially popular with aquascapers from Asia, where it is known under different names, e.g. "Hydrocotyle maritima" and Hydrocotyle sp. "Japan". During the last few years it has spread fast in the European aquarium hobby, too. It belongs to the Australian species Hydrocotyle tripartita. With its clover-shaped small light green leaves and its creeping stems, this water pennywort is really decorative. Moreover, it is a fast grower, can be used in manifold ways, and it is rather undemanding. Hydrocotyle tripartita will show the best development under strong lighting and the injection of CO2. It grows more slowly in low-tech tanks, where it has slanting ascending stems.

This small, delicate Hydrocotyle is highly popular with aquascapers especially from Asia, and is known under diverse names there. It was hardly known in Europe until recently. However, it was imported from Thailand to Italy in 2008 under the name Hydrocotyle sp. "Japan", and from Japan to Germany in 2010.
It is most similar to Hydrocotyle sibthorpioides, however, there are still some differences, the most prominent of them being the deeply indented three- to five-lobed leaves. Not only its nice leaf form that resembles somewhat of clover, but also the fact that it is more undemanding than Hydrocotyle sibthorpioides commonly available in trade. It is also a faster grower and has a more creeping or overhanging growth habit. Under lots of light and CO2 as well as an ample supply of nutrients it grows very fast and may even tend to get invasive.