Salvinia molesta (Giant Salvinia) Care Guide
Salvinia molesta, giant salvinia, is a fast-growing floating fern (Salviniaceae) from Brazil; it is a major invasive species and is legally regulated in many regions.
Overview
Salvinia molesta, giant salvinia or kariba weed, is a free-floating aquatic fern of the family Salviniaceae. Its paired leaves bear distinctive hair-like strands that join at the tips to form eggbeater shapes, and a modified root-like frond hangs submerged below the surface.
Taxonomy
- Family: Salviniaceae
- Genus: Salvinia
- Scientific name: Salvinia molesta
- Common names: giant salvinia, kariba weed
Habitat
The species is native to south-eastern Brazil and thrives in slow-moving, nutrient-rich waters such as lakes, ponds, rivers and marshes. It cannot tolerate high salt concentrations. It has become established in tropical and subtropical regions worldwide, including several US states.
Tank requirements
- Temperature: 20-30 °C (68-86 °F)
- pH: 6.0-8.0
- GH: 3-16 °dGH
- Frond size: 0.5-4 cm
- Lighting: high
- CO2: not required
- Placement: floating
Growth and care
Growth is very fast: under optimal conditions the plant can double in dry weight every 2.2-2.5 days and form dense floating mats. As a vigorous nutrient sponge it helps absorb excess nutrients, but its mats can quickly shade other plants.
Propagation
Reproduction is exclusively asexual, through plant fragments and dormant buds (about five buds per node); the spores it produces are defective and do not form viable offspring.