Isoetes prototypus — prototype quillwort
![Spore cones: Isoetes prototypus. ~ By Arthur Haines. ~ Copyright © 2024 Arthur Haines. ~ arthur.d.haines[at]gmail.com](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Isoetaceae/isoetes-prototypus-sc-ahaines-c.jpg)
![Spore cones: Isoetes prototypus. ~ 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-prototypus-sc-efarnsworth.jpg)
![Spore cones: Isoetes prototypus. ~ By Arthur Haines. ~ Copyright © 2024 Arthur Haines. ~ arthur.d.haines[at]gmail.com](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Isoetaceae/isoetes-prototypus-sc-ahaines-b.jpg)
![Plant form: Isoetes prototypus. ~ By Arthur Haines. ~ Copyright © 2024 Arthur Haines. ~ arthur.d.haines[at]gmail.com](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Isoetaceae/isoetes-prototypus-ha-ahaines-a.jpg)
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Facts
Prototype quillwort is endemic to New England and far eastern Canada (New Brunswick and Nova Scotia). It is very rare in New England, where it is found only in cold clear lakes in Maine.
Habitat
Lacustrine (in lakes or ponds)
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
- 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
- Spore leaf length
- Up to 120 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 120 mm
- Leaf orientation
-
- the vegetative leaves are pressed against 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 120 mm
- Teeth on leaf edges
- the edges of the vegetative leaves have no teeth
-
Place
- Habitat
- aquatic
- New England state
- Maine
- Specific habitat
- in lakes or ponds
-
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 all the spores
- Same or different spores
- there are two different types of spores present
- Spore diameter
- 0.425–0.575
- Spore girdle
- there is no 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 an irregular pattern of ridges and empty spaces (rugulate), or it has minute pits on it (foveolate)
- 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
- absent
- Maine
- present
- Massachusetts
- absent
- New Hampshire
- absent
- Rhode Island
- absent
- Vermont
- absent
Conservation status
Exact status definitions can vary from state to state. For details, please check with your state.
- Maine
- extremely rare (S-rank: S1), threatened (code: T)
From Flora Novae Angliae dichotomous key
6. Isoetes prototypus D.M. Britt. NC
prototype quillwort. ME. Cold, clear lakes with mineral substrate.
Native to North America?
Yes
Sometimes confused with
- Isoetes acadiensis:
- velum covering less than half the sporangium and leaves pliant and curling at the tip (vs. I. prototypus, with the velum covering the entire sporangium and leaves very rigid and straight to the tip).