Lake Quillwort
Isoetes lacustris
Last reviewed: August 2026
Toxicity unknown
Lake Quillwort (Isoetes lacustris) is not listed by the ASPCA Animal Poison Control Center (opens in new tab) or the other sources we check, so we have no verdict for it either way. Absence from those lists is not a clearance. If your pet shows symptoms after eating any plant, call the ASPCA at (888) 426-4435.
Light
part shade
Water
high
Size
2"–8" H × 2"–8" W
Bloom
Aug, Sep, Oct, Nov
Native to
MI, MN, WI
Before you buy
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Lake quillwort is an aquatic fern that forms small clumps of thin, grass-like fronds emerging from underwater or waterlogged soil. This unusual native plant requires consistently wet conditions and is typically found in shallow water or boggy areas. It maintains its green appearance year-round in suitable wet environments.
In an HOA neighborhood
Lake Quillwort takes more care to keep looking intentional in a front yard. Maintenance level: high. Consider it for backyard or mid-zone beds rather than the street edge.
Works well in: backyard only.
- Requires aquatic or bog conditions unsuitable for typical landscaping
- Very small size makes it nearly invisible in standard plantings
- Specialized growing requirements may appear as plant failure
Wildlife value
As a fern, this plant does not produce flowers or attract pollinators, but it provides habitat for aquatic invertebrates and small amphibians in wet environments.
Common questions
- How much sun does Lake Quillwort need?
- Lake Quillwort grows best in part shade conditions.
- When does Lake Quillwort bloom?
- Lake Quillwort blooms in August, September, October, and November.
- Where is Lake Quillwort native?
- Lake Quillwort (Isoetes lacustris) is native to MI, MN, WI, per vouchered herbarium specimen records and regional native plant society lists.
- Is Lake Quillwort HOA-friendly?
- Lake Quillwort takes more care to look intentional in a front yard. Consider it for backyard or mid-zone beds rather than the street edge.
Native range data from vouchered herbarium specimen records and regional native plant society lists. Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.
If something looks wrong
Common plant problems, and what to check first
These come up on almost any plant. Each guide lists the likely causes in the order they are worth ruling out, with one thing to check before you act on any of them, and links to the source it came from.
- It is dying right after planting
- Leaves turning yellow
- Wilting even though I watered it
- Brown crispy leaf tips
- Bugs on the plant
Ready to grow Lake Quillwort? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.
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