Acadian quillwort
Isoetes tuckermanii subsp. acadiensis (Kott) D.F.Brunt.
Acadian quillwort grows as a compact rosette of narrow leaves rooted beneath pond and lake water, less often in rivers. Spores develop inside the widened leaf bases. In Maine, its habitat includes gravel, sand or mud, usually beneath acidic water; maintaining water quality and natural hydrology helps protect these populations. Maine Natural Areas Program: Acadian Quillwort
Botanical name
Kew accepts Isoetes tuckermanii subsp. acadiensis (Kott) D.F.Brunt. and lists Isoetes acadiensis Kott as its homotypic synonym. The database species name therefore resolves to this subspecies. Kew Plants of the World Online: Isoetes tuckermanii subsp. acadiensis
Recognizing the plant
Plants typically have nine to thirty-five leaves, mostly curving backward and measuring about five to twenty-one centimetres long. The larger spores, called megaspores, are about half a millimetre across and have a loose network of smooth, rounded ridges. Microscopic spore ornamentation is important in distinguishing closely similar quillworts. The leaves are typically dark green and form a dense tuft. Maine Natural Areas Program: Acadian Quillwort
Spores and seasonal development
Maine, United States
In Maine, the megaspores mature during August and September. The plant is perennial. Maine Natural Areas Program: Acadian Quillwort
Native range
The accepted subspecies is native to eastern Canada and the northeastern United States. Kew lists New Brunswick, Newfoundland and Nova Scotia, together with Maine, Massachusetts, New Hampshire, New Jersey, New York and Vermont. Kew Plants of the World Online: Isoetes tuckermanii subsp. acadiensis
Botanical sources
- Kew Plants of the World Online: Isoetes tuckermanii subsp. acadiensis
- Maine Natural Areas Program: Acadian Quillwort
Reviewed 2026-10-11. Seasonal development varies with location and growing conditions.