Hygrophila polysperma

Also known as Dwarf hygro, Indian waterweed, Miramar weed, East Indian hygrophila

FreshwaterStemCuttingsSide shoots

Prohibited. Listed as a US federal noxious weed. Illegal to sell, buy, or transport across state lines in the United States. Never release into the wild.

Hygrophila polysperma (Hygrophila polysperma) — Valiromeovich · CC BY-SA 4.0

Care at a glance

Light: Low light
CO2: No CO₂ needed
Growth rate: Fast
Placement: Background
Type: Stem
Temperature: 64–82°F (18–28°C)
pH: 5.0–8.0
Hardness: 2–18 dGH
Max height: 17.7 in (45 cm)
Spread: 3.1 in (8 cm)
Nutrient uptake: Root + water column
Growth region: Submersed or emersed
Difficulty: Beginner
Origin: South and Southeast Asia (India, Bhutan, Bangladesh, Nepal)
Family: Acanthaceae

Overview

Plant cuttings in loose bunches in the mid to background, spacing stems so light reaches the lower leaves. It is one of the toughest plants in the hobby, growing fast in low light with no CO2 and feeding from both water column and substrate, so it is excellent for cycling new tanks and soaking up excess nutrients. The main pitfall is its speed: it needs frequent trimming or it shades everything below it, and trimmings must be binned rather than released into waterways because it is invasive.

In the wild

Hygrophila polysperma comes from streams, ditches, and marshes across South and Southeast Asia, including India, Bangladesh, Nepal, and Bhutan. It grows both submersed as a soft-stemmed water plant and emersed along muddy banks during low water. It tolerates a very wide range of conditions, which is why it has naturalized and is now an invasive weed in parts of North America and Europe.

Good to know

It belongs to the family Acanthaceae, the same family as the larger Hygrophila corymbosa. As a stem plant it grows upward from a single shoot, throwing pairs of opposite leaves and rooting readily at any node that touches substrate. The popular Rosanervig variety, with pink veining caused by a controlled nutrient variegation, was named and distributed by the Danish nursery Tropica.

Did you know

It grows so aggressively that it is a federally listed noxious weed in the United States, illegal to sell or transport across state lines, even though it remains one of the most recommended beginner plants elsewhere in the world.