TankBud

Echinodorus decumbens

Also known as Aquarius decumbens

FreshwaterRosettePlantlets

Care at a glance

Light
Medium light
CO2
CO₂ beneficial
Temperature
72–82°F
22–28°C
Max height
19.7 in
50 cm
Growth rate
Fast
Placement
Background
Type
Rosette
pH
5.0–7.0
Hardness
0–18 dGH
Spread
11.8 in (30 cm)
Nutrient uptake
Root feeder
Growth region
Submersed or emersed
Difficulty
Easy
Family
Alismataceae
Origin
Eastern Brazil (Rio Surubim, Piaui)

Overview

Echinodorus decumbens is an easy, fast-growing sword plant for the background of a larger tank.

Did you know

Echinodorus decumbens was discovered by Christel Kasselmann, author of the standard reference book on aquarium plants. She collected it on the Rio Surubim in 1994 and later described it.

Caring for Echinodorus decumbens

Plant Echinodorus decumbens in a deep, nutrient-rich substrate and leave the crown just above the surface. It is a root feeder, so add root tabs once it is established.

Medium light or better is enough. It grows without injected CO2, though added CO2 noticeably speeds it up. Despite its soft-water home, it tolerates a wide range of hardness, from 0 to 18 dGH. Keep it at 72 to 82°F (22 to 28°C) and a pH of 5 to 7.

It reaches around 50 cm underwater, and more as it matures. To propagate it, pin a plantlet from a flower stalk down and cut it free once it has rooted.

Good to know

Echinodorus decumbens is a sword plant in the family Alismataceae. Its epithet decumbens means lying down. The name fits its flower stalks, which trail rather than stand upright and form plantlets when grown emersed. Molecular work has since moved most swords into the genus Aquarius, so its accepted name is now Aquarius decumbens. Shops still sell it as an Echinodorus.

In the wild

Echinodorus decumbens comes from the Rio Surubim in Piaui, eastern Brazil. It grows on the banks and in the inundation zones of the river, in soft, slightly acidic water. Like other swords, it lives emersed for part of the year and submersed when the river floods.

Common questions

Does Echinodorus decumbens need to be planted in the substrate?

Yes. Bury the roots and leave the crown, where the leaves join, just above the substrate.

Does Echinodorus decumbens need CO2?

No, but it helps. Echinodorus decumbens can grow without injected CO2, and added CO2 makes it grow faster.

How much light does Echinodorus decumbens need?

Echinodorus decumbens wants medium light. A light sold for planted tanks covers it.

Does Echinodorus decumbens need root tabs?

Yes. Echinodorus decumbens draws much of its food through its roots. Push root tabs in near it, or grow it in a nutrient-rich soil.

How do you propagate Echinodorus decumbens?

Echinodorus decumbens propagates by plantlets. Small plantlets form on the plant and can be detached once they have a few roots.

How tall does Echinodorus decumbens grow?

Echinodorus decumbens grows to about 19.7 in (50 cm) tall. It grows fast, so expect to trim it often.

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