Ferny Azolla

Also known as:
Water Velvet
Tropical Africa, Asia, Australia

General description

Tiny free-floating aquatic fern, forming red-coloured mats (green in shaded areas). Plants 25 x 20 mm, triangular or 5-angled in outline, regularly branched. Leaves usually not overlapping, green turning red. Roots to 5 cm long; with fine, lateral rootlets.

Ponds, lakes, dams

Downstream flow, on equipment, waterfowl.

Dense seasonal mats inhibit growth of underwater plants. Decreases surface water mixing, lowers oxygen levels, causes stagnation.

Site management

Little point in controlling as it re-establishes quickly. Better to expose site to prevailing summer winds (eg. remove windward shelter) & increase shading on north side of narrow waterways. In dams & ponds, raising spring-summer water level exposes surface to wind.

Recommended approaches

1. Rake weed onto dry land. Carry out when windy to assist drift. A floating boom will concentrate plants into one area.

Caution: when using any herbicide or pesticide PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and safety requirements are followed.

Search tags

RPMS status

Not a legally declared pest plant
ferny azolla - Main species image