Mermaid Weed

Proserpinaca palustris

A stem plant with saw-toothed, needle-like leaves that turn copper and red in strong light. It changes shape completely once it settles under water — the leaves you buy are not the leaves you keep.

Light: high
Difficulty: medium
Height: 10 – 30 cm (3.9 – 12 in)
Temperature: 10 – 28 °C (50 – 82 °F)

Leaf colour: green, red +1 green, red, bronze or brown
Plant type: stem plant
Growth rate: medium
CO₂ demand: high
Tolerates light: medium – high
pH: 5 – 7
Carbonate hardness: 0 – 18 °dKH
General hardness: 0 – 30 °dGH
Placement: red accent, background +1 red accent, background, midground
Propagation: cuttings
Grows emersed: yes

Appearance

Stems 10–30 cm tall. Grown above water the leaves are broad and toothed; under water they turn long, narrow and finely serrated. Colour runs from golden green to solid red depending on light and iron.

Keeping

Demanding: it needs strong light and added carbon dioxide for the colour and the narrow leaf form. In dim light it stays green and coarse. The change of leaf shape after planting is normal and takes a few weeks.

Placement

The middle and back of the tank, in a group where its texture contrasts with broad-leaved neighbours.

Propagation

Cut the top of a stem and plant it; the old stem branches from the cut.

Water conditions match

The water suits 835 of 1249 species in the catalogue — these are the ones people look up most often.

Butterflyfish Julii Corydoras Red-finned Parotocinclus Gastromyzon monticola Egg-shaped Goldfish Flame Tetra Gardner's Killifish African Tetra Hypsolebias picturatus Common Zacco Labeo Bicolor Gambusia Flying barb Gastromyzon scitulus Albino Zebra Danio Geophagus Brokopondo Homaloptera bilineata Red-tailed Rasbora Boraras naevus Lampeye Killifish Spotted Raphael Catfish Corydoras melanotaenia Festivum cichlid Pseudomugil paskai

Will eat this plant

These species damage plants, especially when their diet is short of vegetable food.

Bengal Loach Zebra Loach Burmese Border Loach Emperor Botia Marbled Headstander Pellegrin's Leporinus Leporinus striatus False Black Tetra Common Metynnis Mylossoma duriventre Red Whiptail Catfish Moonlight Gourami Melanotaenia parva

Will uproot it

These species dig through the substrate and pull rooted plants out.

Marble Loach Peacock Eel Forktail Loach Guntea Loach Long-nosed Loach Horseface Loach Pearlscale Black Moor Goldfish Shubunkin Painted Pleco Featherfin Synodontis Reddish Mystus Catfish Blue Acara Geophagus altifrons Geophagus winemilleri Pearl Cichlid Red-spotted Cichlid Haplochromis philander Red Chromide Jack Dempsey cichlid

Matching water does not mean the fish will leave the plant alone.

The same plant with a different look: light, water and care are shared with the species.

Other varieties: Proserpinaca palustris 'Cuba'

Scientific and other names, conservation status

Other scientific names: Proserpinaca heterophyla, Proserpinaca palustris latifolia, Proserpinaca platycarpa, Proserpinaca serrata, Proserpinaca tuberculata, Trixis palustris
Proserpinaca palustris: L.
Family: Haloragaceae
Conservation status: LC

Mermaid Weed

Tank conditions

Care and keeping