Piedmont quillwort (Isoetes malinverniana) care guide

Group
Plants
Other names
Piedmont quillwort, Quillwort
Family
Isoetaceae (quillwort family)
Origin
Italy (Piedmont, northern Italy); endemic
Water
freshwater
Maximum size
20 cm
Temperature
10–22°C
pH
6–7.5
Hardness
2–10 dGH
Care level
expert
Lighting
Medium light; CO2 helpful

Care

Piedmont quillwort is a quillwort, a primitive spore-bearing relative of the clubmosses, found only in northern Italy. It is critically endangered in the wild and a conservation breeding programme exists for it. Like other Isoetes it grows from a small corm and sends up a tuft of narrow, hollow, quill-like leaves. Its aquarium use is barely documented. If you have cultivated stock, grow it as a foreground to midground clump in a fine, nutrient-rich substrate, planted with the corm just at the surface. Quillworts grow slowly and take much of their carbon through the roots, so a rich substrate matters more than heavy fertilising of the water. It comes from a temperate region and is best kept cool; it is unlikely to do well long-term in a warm tropical tank and suits coldwater tanks or ponds better. Water figures are our estimate, not from the sources. Because it is critically endangered, plants must never be collected from the wild. Only buy or sell plants of known cultivated origin. Sources: Wikipedia (en.wikipedia.org/wiki/Isoetesmalinverniana); Wikipedia (en.wikipedia.org/wiki/Isoetes); Wikipedia, List of freshwater aquarium plant species. Checked October 2026.

Breeding

Quillworts reproduce by spores formed in the swollen leaf bases; each leaf carries either many small spores or fewer large ones. Spore raising is slow and specialist work. Older plants can sometimes be divided at the corm, but this is not documented for this species.

Compatibility and tank mates

Best in unheated or coldwater tanks and ponds with temperate fish such as minnows, sticklebacks or small goldfish; large goldfish and koi may eat or uproot it. It suits tropical tanks poorly over the long term.

Last updated 8 October 2026. Community-edited care guide on Aquatic-Auctions.

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