The open plant encyclopedia
Snap a photo or search by any name to see how to care for it, where it comes from, whether it's safe, and a 3D model you can turn.
The plants people record most in your country, and ones that grow there wild.
Filter by what you want to do, shape, origin, country, care and safety.
Pilularia americana
American pillwort is a small aquatic fern in the Marsileaceae family with grass-like stalks and no true leaf blades. It grows rooted in wet mud or in shallow water, and it is easy to overlook.
Pilularia americana, the American pillwort, is an unusual species of fern. The fronds essentially consist of the petioles only, any form of flattened laminae having been lost. It is in the aquatic fern family Marsileaceae, and is related to the water clovers and also to Azolla and Salvinia.
This plant is easily grown given a suitable habitat and kept uncrowded.
The pillwort also may die out for drier or colder parts of the season, regenerating the next year from the sporocarps. While it is in the aquatic fern group, it prefers to be emergent (in shallow water, with fronds emerging into the air) or growing completely emersed (fronds completely out of water), though preferring to be rooted in wet mud.
The range of the American pillwort is well-established throughout much of California and south-central Oregon. However, mostly only local occurrences have been found elsewhere in eastern North America. It is uncertain whether this reflects a genuinely sporadic occurrence, or whether this is a reflection of the fact that this is a small, grasslike, extremely easily overlooked plant. Close examination is often necessary to ascertain that this is a Pilularia. The species also occurs through Central and South America, although scientific investigation may confirm those plants to be a separate species, P. mandoni A. Braun.
Text excerpted from the Wikipedia article Pilularia americana by its contributors, under CC BY-SA 4.0; the excerpts and the care summary drawn from them are shared under the same licence.
The care summary was written by AI (Claude, Anthropic) from the sources on this page, with general growing knowledge where they are silent. Check before relying on it.
Life form, climate and native range: World Checklist of Vascular Plants, Royal Botanic Gardens, Kew (CC BY 3.0), reformatted; see Plants of the World Online.
