Selaginella willdenowii

The “umbrella fern” is a large spikemoss species that is almost always labelled Selaginella wildenowii in the trade. The correct spelling of the species name is S. willdenowii¹ (after the botanist Carl Ludwig von Willdenow). Despite the designation “spikemoss” (Moosfarn), Selaginella species are not true ferns but belong to the lycophytes. The spikemosses are an ancient group of relatives that has existed since the Carboniferous (coal age), probably contains more than 700 species and is distributed worldwide, predominantly in tropical and subtropical regions. Their closest living relatives are the completely different-looking Isoetes species (quillworts).²

Selaginella willdenowii is often offered in the aquarium trade as a “decorative plant”, but it is not suitable as an aquarium plant and sooner or later dies off in water.

However, S. willdenowii, which originates from Southeast Asia, can be cultivated in warm, humid terrariums. This spikemoss species, which can grow up to 6 metres tall, is not a marsh plant and does not tolerate permanently wet soil. It grows upright, forms long aerial roots growing towards the ground and, as an older plant, tends to climb.³