Isoetes acadiensis — Acadian quillwort
![Spores: Isoetes acadiensis. ~ By Elizabeth Farnsworth. ~ Copyright © 2024 New England Wild Flower Society. ~ Image Request, images[at]newenglandwild.org](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Isoetaceae/isoetes-acadiensis-sp-efarnsworth.jpg)
![Leaves: Isoetes acadiensis. ~ By Jennifer Garrett. ~ Copyright © 2024 Jennifer Garrett. ~ gemmiferg[at]gmail.com](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Isoetaceae/isoetes-acadiensis-le-jgarrett.jpg)
![Inflorescences: Isoetes acadiensis. ~ By George Yatskievych. ~ Copyright © 2024 George Yatskievych. ~ george.yatskievych[at]mobot.org](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Isoetaceae/isoetes-acadiensis-in-gyatskievych1.jpg)
![Vegetative leaves: Isoetes acadiensis. ~ By Lytton John Musselman. ~ Copyright © 2024 lmusselm[at]odu.edu; http://www.odu.edu/~lmusselm/. ~ lmusselm[at]odu.edu ~ www.odu.edu/~lmusselm/plant/](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Isoetaceae/isoetes-acadiensis-tr-lmusselman1.jpg)
![Plant form: Isoetes acadiensis. ~ By Arthur Haines. ~ Copyright © 2024 Arthur Haines. ~ arthur.d.haines[at]gmail.com](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Isoetaceae/isoetes-acadiensis-ha-ahaines.jpg)
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Facts
Acadian quillwort is rare in New England, with a few populations in Maine, Massachusetts and New Hampshire representing the southern limit of its distribution along the northern coastal plain. An inhabitant of shallow water of low-nutrient lakes and slow-moving streams, Acadian quillwort is sensitive to changes in hydrology and water quality, especially nutrient runoff.
Habitat
Lacustrine (in lakes or ponds), riverine (in rivers or streams)
New England distribution
Adapted from BONAP data
Native: indigenous.
Non-native: introduced (intentionally or unintentionally); has become naturalized.
County documented: documented to exist in the county by evidence (herbarium specimen, photograph). Also covers those considered historical (not seen in 20 years).
State documented: documented to exist in the state, but not documented to a county within the state. Also covers those considered historical (not seen in 20 years).
Note: when native and non-native populations both exist in a county, only native status is shown on the map.
Found this plant? Take a photo and post a sighting.
enlargeCharacteristics
- Habitat
- aquatic
- New England state
-
- Maine
- Massachusetts
- New Hampshire
- Leaf shape
- the vegetative leaves are long and narrow
- Spore leaf arrangement
- the sporophylls are located in a whorl at the base of the plant
- Form of shoot
- NA
- Horizontal stem
- NA
- Leaf differences
- the vegetative leaves within a node are all similar in size and shape
- Teeth on leaf edges
- the edges of the vegetative leaves have no teeth
- Constriction zones
-
- NA
- NA
- Spore leaf length
- Up to 200 mm
- Leaf outline
- the vegetative leaves are long and very narrow (linear)
-
Clonal plantlets
- Gemma arrangement
- NA
- Gemma shape
- NA
- Gemma width
- 0 mm
-
Leaves
- Leaf differences
- the vegetative leaves within a node are all similar in size and shape
- Leaf length
- Up to 200 mm
- Leaf orientation
-
- the vegetative leaves curve outwards and downwards from the main stem
- the vegetative leaves spread away from the stem
- the vegetative leaves spread slightly away from the stem, at a steep angle
- Leaf outline
- the vegetative leaves are long and very narrow (linear)
- Leaf ranks
- NA
- Leaf shape
- the vegetative leaves are long and narrow
- Pores on leaves
- there are no apparent pores on the vegetative leaves
- Spore leaf length
- Up to 200 mm
- Teeth on leaf edges
- the edges of the vegetative leaves have no teeth
-
Place
- Habitat
- aquatic
- New England state
-
- Maine
- Massachusetts
- New Hampshire
- Specific habitat
-
- in lakes or ponds
- in rivers or streams
-
Spores or spore cones
- Cone base at stem
- NA
- Cone stalk branching
- NA
- Cone thickness
- 0 mm
- Cone width
- 0 mm
- Length of cone
- 0 mm
- Number of cones
- 0
- Quillwort itssue covering spores
- the velum covers less than half of the spores
- Same or different spores
- there are two different types of spores present
- Spore diameter
- 0.3999–0.64999
- Spore girdle
- there is a smooth girdle alongside the equatorial ridge
- Spore leaf arrangement
- the sporophylls are located in a whorl at the base of the plant
- Spore leaf lifespan
- the sporophylls remain green for the life of the plant
- Spore leaf orientation
- the sporophylls slant upwards at a steep angle
- Spore leaf shape
- the spore-bearing leaves are long and narrow
- Spore leaf teeth
- The edges of the spore-bearing leaves are smooth, and without teeth
- Spore texture
- the spore surface has a net-like pattern on it (reticulate)
- Sporophyll ranks
- NA
- Sterile tip of cone
- NA
-
Stem, shoot, branch
- Branch cross-section
- NA
- Branch form
- NA
- Constriction zones
-
- NA
- NA
- Form of shoot
- NA
- Horizontal stem
- NA
- Horizontal stem length
- 0 mm
- Horizontal stem thickness
- 0 mm
- Stem height
- 0 mm
Wetland status
Occurs only in wetlands. (Wetland indicator code: OBL)
In New England
Distribution
- Connecticut
- present
- Maine
- present
- Massachusetts
- present
- New Hampshire
- present
- Rhode Island
- absent
- Vermont
- absent
Conservation status
Exact status definitions can vary from state to state. For details, please check with your state.
- Maine
- rare (S-rank: S2), special concern (code: SC)
- Massachusetts
- extremely rare (S-rank: S1), endangered (code: E)
- New Hampshire
- historical (S-rank: SH), endangered (code: E)
From Flora Novae Angliae dichotomous key
1. Isoetes acadiensis Kott NC
Acadian quillwort. MA, me, nh; eastern New England. Slightly acidic lakes and slow- moving streams.
Native to North America?
Yes
Sometimes confused with
- Isoetes hieroglyphica:
- megaspores 0.55–0.7 mm in diameter, averaging more than 0.6 mm, and leaves abruptly tapering to the tip (vs. I. acadiensis, with megaspores megaspores 0.4–0.65 mm in diameter, averaging less than 0.6 mm, and leaves gradually tapering to the tip).
- Isoletes tuckermannii:
- megaspores with a papillate girdle, cristate to reticulate with irregular, roughened crests (vs. I. acadiensis, with megaspores with a smooth girdle, reticulate with smooth, rounded crests).