Hygrophila polysperma 'Rosanervig' Sunset Hygrophila

Hygrophila polysperma 'Rosanervig' is as undemanding as standard H. polysperma, getting 20-40 cm tall and 5-8 cm wide. It is also known under the trade names 'Sunset' and 'Marmor' (i.e. Marble) and has a striking variegation with light nerves. But if you want deep-pink leaves you must provide intensive light. Otherwise the nerves are rather white. The distinctive light colouring of the leaf nerves is probably caused by a virus which prevents chlorophyll from being produced in the cells around the leaf ribs, making them white. However, this virus does not affect other plants in the aquarium. Hydrophila polysperma "Sunset", in Europe sold under the name "Rosanervig", has its origins in the Danish aquatic plant nursery Tropica. One special characteristic of this variety are the white-coloured leaf veins. They are not the symptom of a nutrient deficiency, though. It is assumed that a virus prevents the tissue around the veins from producing chlorophyll. This virus specialises in this variety only and thus poses no danger at all for the rest of the aquarium plants. This variety of the so well-known robust Asian H. polysperma has become a very highly coveted aquarium plant. This undemanding red-coloured plant is very interesting as it is probably the easiest plant of that hue in cultivation. It grows under almost any conditions. Temperatures between 18 and 28℃, pH values in the range of 5 to 8 and a water hardness of soft to hard are tolerated very well, which shows how adaptable this plant is. It does not require lots of light and CO₂, however, when provided with these factors its reddish colour gets more intensive. Iron also plays an important role for the reddish hue, too, as the plant colour tends to fade to shades of pale white if there is insufficient iron in the water column. Like so many other fast growers, this plant tends to grow horizontally along the substrate. In many cases, this habit is caused by lots of light and helps the plant to cover as much room as possible before it resumes vertical growth. You can easily prevent this phenomenon by planting the stems very densely or by increasing the phosphate (PO₄) level in the tank. Propagation and trimming are very easy. Just cut off a shoot and re-plant it in the substrate. Cutting back the main shoot results in many lateral shoots, and thus frequent trimming results in beautiful very bushy plants. Hydrophila polysperma "Sunset", or "Rosanervig" is a red stem plant with lots of potential.

Flowgrow

Light leaf veins Light green, yellowish to red hues Easy to cultivate

Hygróphila polyspérma (Roxb.) T.Anderson

Acanthaceae

Hygrophila

Middle Ground

very easy

very fast

need

5-8

4-35℃

2-21 dKH

0-30 °dGH

Cuttings

yes

very colourful plant for accents