Ranalisma rostratum

Also known as Ranalisma rostrata, Dwarf chain amazon, Ranalisma

FreshwaterCarpetingRunners

Care at a glance

Light: Medium light
CO2: CO₂ beneficial
Temperature: 68–82°F; 20–28°C
Max height: 3.1 in; 8 cm

Growth rate: Medium
Placement: Foreground
Type: Carpeting
pH: 6.0–7.5
Hardness: 0–30 dGH
Spread: 3.9 in (10 cm)
Nutrient uptake: Root feeder
Growth region: Submersed or emersed
Difficulty: Medium
Family: Alismataceae
Origin: Tropical Asia (China, India, Malaysia, Vietnam)

Overview

A rosette plant that behaves as a spreading foreground carpet, sending runners out to knit clumps into a lawn 4 to 6 cm tall. It is a root feeder, so a nutrient-rich substrate or root tabs help, and it shows iron deficiency quickly as pale yellow new leaves. It prefers medium to strong light with CO2 for compact growth; thin dense stands and trim stray runners.

In the wild

Native to shallow wetlands and marshy ground across tropical Asia, including parts of China (Hunan, Jiangxi, Zhejiang, where it is very rare), India, peninsular Malaysia and Vietnam. Emersed it forms small spoon-shaped leaves and white flowers; submersed it puts out narrow light-green ribbon leaves. It creeps outward on runners to form a low lawn.

Good to know

A member of the water-plantain family (Alismataceae), so it is a genuine relative of the true chain swords (Helanthium/Echinodorus) rather than a grass. The correct botanical name is Ranalisma rostratum; the widely used 'rostrata' is a grammatically incorrect ending. The submersed form closely resembles the light-green form of Helanthium tenellum and is often confused with it.

Did you know

Did you know this plant has stayed a genuine rarity in the Western hobby despite being an easy grower, showing up mostly in Asian nurseries and rarely in European or American shops.