Piauí Sword

Aquarius decumbens

A tall sword plant with very narrow, long-stalked leaves, found in a single river in eastern Brazil. Its airy shape lets you see the background through it, which few large plants allow.

Light: medium–high
Difficulty: easy
Height: 30 – 50 cm (12 – 20 in)
Temperature: 18 – 30 °C (64 – 86 °F)

Plant type: rosette
Growth rate: fast
Tolerates light: medium – high
pH: 5 – 7
Carbonate hardness: 0 – 21 °dKH
General hardness: 0 – 30 °dGH
Placement: background, midground
Propagation: plantlets on the inflorescence
Grows emersed: yes

Appearance

Narrow blades on long stalks in a loose upright rosette, 30–50 cm tall in an aquarium and taller still in ideal conditions. A group of large plants at the back reads almost like a stand of reeds.

Keeping

Easy and vigorous, with two preferences worth knowing: good light and a nutritious substrate, and warmth — it comes from hot eastern Brazil, likes 25 °C and upward, and grows well even around 30 °C. That makes it one of the better plants for a discus tank. Although it grows naturally in very soft, slightly acidic water, it does fine in medium-hard, slightly alkaline water.

Placement

The middle or back of a tall tank. Because the leaves are narrow it shades very little, so small-leaved stem plants can be grown around it.

Propagation

By young plants that form on the creeping flower stalk.

Water conditions match

The water suits 841 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: Echinodorus decumbens, Echinodorus decumbens Topf

Scientific and other names, conservation status

Other scientific names: Echinodorus decumbens
Family: Alismataceae

Piauí Sword

Tank conditions

Care and keeping