TankBud

Cryptocoryne cordata

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

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 + water column
Growth region
Submersed or emersed
Difficulty
Easy
Family
Araceae
Origin
Malay Peninsula and Thailand

Overview

An undemanding slow grower with attractive ruffled, spear-shaped leaves that range from green to bronze and reddish. It prefers low to medium light, matching its shaded stream habitat, and a nutrient-rich substrate with root tabs. Plant it and give it time to settle before expecting new growth, then it slowly spreads by runners. Stable water reduces the risk of crypt melt.

In the wild

A widespread species complex from Southeast Asia. Typical Cryptocoryne cordata grows 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, shaded riverbanks, and swampy ground, often emersed during dry periods.

Good to know

Described by William Griffith. It is a large species complex with several named varieties (cordata, siamensis, diderici, grabowskii) that differ in leaf shape, color, and water chemistry. The old aquarium name Cryptocoryne blassii refers to this species. Many trade plants sold simply as 'cordata' are actually var. siamensis.

Did you know

The soft-acid-water Malayan form and the hard-water Thai var. siamensis are the same species living in completely opposite water chemistry, which is why so many hobbyists get confused about whether 'cordata' wants soft or hard water.

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