TankBud

Cryptocoryne cordata

Also known as Cryptocoryne cordata var. siamensis, Cryptocoryne blassii, Cryptocoryne siamensis

FreshwaterRosetteRunners

Care at a glance

Light
Low light
CO2
CO₂ beneficial
Temperature
72–82°F
22–28°C
Max height
9.8 in
25 cm
Growth rate
Slow
Placement
Midground
Type
Rosette
pH
6.0–7.5
Hardness
2–12 dGH
Spread
5.9 in (15 cm)
Nutrient uptake
Root feeder
Growth region
Submersed or emersed
Difficulty
Easy
Family
Araceae
Origin
Malay Peninsula and Thailand

Overview

Cryptocoryne cordata is an undemanding crypt for the midground. Its ruffled, spear-shaped leaves range from green to bronze and reddish. It is an easy plant for a low-tech tank.

Did you know

Many plants sold simply as Cryptocoryne cordata are actually var. siamensis. The Malayan form and the Thai siamensis are one species in opposite water chemistry. That is why hobbyists get confused about whether cordata wants soft or hard water.

Caring for Cryptocoryne cordata

Plant Cryptocoryne cordata in a nutrient-rich substrate, with the roots buried and the crown just above the surface. Give it time to settle before you expect new growth. Stable water reduces the risk of crypt melt, so plant it once and avoid big swings in conditions.

It is happy in low light, which matches its shaded stream habitat. It grows without injected CO2, and added CO2 makes it grow faster. It is a root feeder, so push root tabs in near it. It suits 72 to 82°F (22 to 28°C) and a pH of 6 to 7.5.

Growth is slow, and it rarely needs trimming. Once settled, it slowly spreads by runners. Cut a young plant free once it has roots and plant it where you want it.

Good to know

Cryptocoryne cordata was described by William Griffith. It is a large species complex with several named varieties, cordata, siamensis, diderici and grabowskii, which differ in leaf shape, color and water chemistry. The old aquarium name Cryptocoryne blassii refers to this species, and it is also listed under the trade name Rosanervig.

In the wild

Cryptocoryne cordata is a widespread species complex from Southeast Asia. Typical plants grow in acidic, soft waters of the Malay Peninsula, while var. siamensis occurs in shaded, calcareous flowing waters of southern Thailand. It lives in slow streams, on shaded riverbanks and in swampy ground, and it often grows emersed during dry periods.

Common questions

Does Cryptocoryne cordata need to be planted in the substrate?

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

Does Cryptocoryne cordata need CO2?

No, but it helps. Cryptocoryne cordata can grow without injected CO2, and added CO2 makes it grow faster.

How much light does Cryptocoryne cordata need?

Cryptocoryne cordata is a low-light plant, and the light that comes with a standard tank kit is enough for it.

Does Cryptocoryne cordata need root tabs?

Yes. Cryptocoryne cordata 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 Cryptocoryne cordata?

Cryptocoryne cordata propagates by runners. New plants grow along its runners. Cut one free once it has roots and plant it.

How tall does Cryptocoryne cordata grow?

Cryptocoryne cordata grows to about 9.8 in (25 cm) tall. It grows slowly and rarely needs trimming.

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