Bolbitis Difformis

Care at a glance

Overview

Tie or glue the rhizome to wood or stone and keep it off the substrate, a buried rhizome rots. Fully submersed it is very slow and stays under about 7 cm, so it works as a foreground or midground carpet on hardscape but tests your patience. It does best in clean, soft, slightly acidic water with gentle light, and CO2 plus regular water changes keep the delicate fronds algae-free.

In the wild

This dwarf fern comes from the Philippine island of Negros, in humid forest near Lake Balinsasayao, where it creeps over damp rock and soil at the water's edge. In the wild it is really a marsh and streamside plant, forming low mats with its trailing rhizome rather than a tall stand.

Good to know

It is a true fern in the family Dryopteridaceae, a compact form of Bolbitis heteroclita distinct from the larger African water fern Bolbitis heudelotii that it is often confused with in the trade. Submersed it produces smaller, coarser pinnate fronds than the finely divided leaves it grows on land.

Did you know

It actually grows faster and lusher out of water than in it, which is why keepers get their best carpets from this fern in paludariums and terrariums rather than fully flooded tanks.

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