Plants
Sunset Hygro
Hygrophila polysperma 'Rosanervig'
Origin: 'Rosanervig' is a decorative variegated form of the dwarf hygro (Hygrophila polysperma), developed in cultivation. The parent species comes from South and Southeast Asia.
Also known as: Hygrophila polysperma 'Rosanervig', Dragonfly hygro
Fact sheet
- Height
- 40 cm
- Temperature
- 20–28 °C
- pH
- 6–7.8
- Lighting
- Medium
- CO₂
- Recommended
- Growth rate
- Medium
- Placement
- Midground, Background
Overview
The sunset hygro ('Rosanervig') is a beautiful variegated form of the undemanding dwarf hygro, with pink-white veins on a greenish leaf. The 'sunset' effect comes from a partial lack of chlorophyll along the veins, so the plant needs more light than the plain dwarf hygro and grows a little slower. Yet it keeps the hardiness of the parent and needs no CO2. It is an excellent way to add a light, contrasting accent without finicky red plants.
Appearance
Upright stems bear opposite oblong-lanceolate leaves 3–6 cm long. Contrasting pink-white veins run across the greenish blade, especially vivid on the young upper leaves. Under strong light the tips turn pinker. Height is up to 40 cm.
Care
It needs medium to strong light for vivid veins, 20–28 °C, pH 6.0–7.8. CO2 is optional but improves growth and colour. It grows moderately fast; basic fertilisers suffice. Otherwise it is as hardy as the parent dwarf hygro.
Fertilizing
It feeds through roots and leaves. Iron and micronutrients help vivid veins; macronutrients speed growth. Moderate fertiliser demand.
Breeding
It propagates by top cuttings; the stem puts out side shoots. The variegation is stably passed on vegetatively.
Fun facts
The pink-white veins result from a partial lack of chlorophyll, so the plant needs more light. The form is also called sunset hygro. It is one of the easiest ways to get a variegated accent in an aquarium.