Gymnocarpium dryopteris — northern oak fern
![Leaf: Gymnocarpium dryopteris. ~ By Arthur Haines. ~ Copyright © 2024 Arthur Haines. ~ arthur.d.haines[at]gmail.com](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Woodsiaceae/gymnocarpium-dryopteris-le-ahaines.jpg)
![Plant form: Gymnocarpium dryopteris. ~ By Bruce Patterson. ~ Copyright © 2024 Bruce Patterson. ~ foxpatterson[at]comcast.net](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Woodsiaceae/gymnocarpium-dryopteris-ha-bpatterson.jpg)
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Facts
Northern oak fern produces new fronds all summer long. The Cree Indians crushed oak fern leaves to repel mosquitoes and to treat bites.
Habitat
Cliffs, balds, or ledges, forests, talus and rocky slopes
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
- terrestrial
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Leaf divisions
-
- the leaf blade is three times compound (divided into leaflets, which are further divided into leaflets, which are further divided into leaflets), or more
- the leaf blade is twice compound (divided into leaflets, which are further divided into leaflets)
- Plant growth form
- the leaves grow from a rhizome growing at or below the ground
- Spore-bearing leaflets
- the spore-bearing fronds are similar in size and shape to the sterile fronds
- Sorus shape
- the sori are circular or kidney-shaped
- Leaf stalk scales
- the leaf stalk has scales
- Leaf stalk hairs
- the leaf stalk has hairs
- Leaf blade length
- 7–20 cm
- Leaf vein tips
- the veins go all the way to the edge of the leaf blade
-
Growth form
- Life form
- the plant is herbaceous and terrestrial
- Life stage
- the plant is visible as a typical leaf-bearing fern (sporophyte)
- Spore-bearing leaflets
- the spore-bearing fronds are similar in size and shape to the sterile fronds
-
Leaves
- Features of leaves
- there are no special features on the leaves
- Leaf blade length
- 7–20 cm
- Leaf blade shape
- the leaf blades are roughly triangular
- Leaf blade tip shape
- the tip of the leaf blade is rounded
- Leaf blade width
- At least 10 cm
- Leaf divisions
-
- the leaf blade is three times compound (divided into leaflets, which are further divided into leaflets, which are further divided into leaflets), or more
- the leaf blade is twice compound (divided into leaflets, which are further divided into leaflets)
- Leaf lifespan
- the leaves drop off in winter
- Leaf stalk color
-
- green
- yellow to brown
- Leaf stalk hairs
- the leaf stalk has hairs
- Leaf stalk length
- 90–280 mm
- Leaf stalk relative length
- the leaf stalk is more than three quarters as long as the blade
- Leaf stalk scale location
- the scales are present only on the lower half of the leaf stalk
- Leaf stalk scales
- the leaf stalk has scales
- Leaf stalk vessels
- 2 bundles
- Leaf vein branching
- the secondary veins of the leaf blade are not branched
- Leaf vein tips
- the veins go all the way to the edge of the leaf blade
- Leaflet relative size
- the bottom leaflets are at least one and a half times as long as the leaflets from the middle of the frond
- Leaflet stalks
-
- the leaflets are stalked
- the leaflets do not have stalks
- Lobe or leaflet length
- 20–120 mm
- Lobe or leaflet pairs
- 5–15
- Lobe or leaflet shape
- the lobe or leaflet is rectangular but with rounded ends (oblong)
- Lobe or leaflet width
- 38–120 mm
- Plant growth form
- the leaves grow from a rhizome growing at or below the ground
- final leaf segment margin
-
- the topmost lobe or leaflet of the leaf blade has a smooth or lobed edge
- the topmost lobe or leaflet of the leaf blade has an edge with teeth
-
Place
- Habitat
- terrestrial
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Specific habitat
-
- cliffs, balds, or ledges
- forests
- talus or rocky slopes
-
Spores or spore cones
- Sorus features
- there are no special features on the sorus
- Sorus shape
- the sori are circular or kidney-shaped
- Sporangia location
- the spores are clustered on sori on the lower surface of the leaf blade
- Sporangium type
- the sporangia are opaque without an annulus and usually without a stalk (leptosporangiate)
- Spore forms
- there is only one type of spore present
Wetland status
Usually occurs in non-wetlands, but occasionally in wetlands. (Wetland indicator code: FACU)
In New England
Distribution
- Connecticut
- present
- Maine
- present
- Massachusetts
- present
- New Hampshire
- present
- Rhode Island
- present
- Vermont
- present
Conservation status
Exact status definitions can vary from state to state. For details, please check with your state.
- Massachusetts
- unranked (S-rank: SNR)
- Rhode Island
- extremely rare (S-rank: S1), state threatened (code: ST)
From Flora Novae Angliae dichotomous key
1. Gymnocarpium dryopteris (L.) Newman N
northern oak fern. Carpogymnia dryopteris (L.) A. & D. Löve; Dryopteris dryopteris (L.) Britt.; Polypodium dryopteris L. • CT, MA, ME, NH, RI, VT. Forests, base of cliffs, talus slopes.
1×G. disjunctum (Rupr.) Ching. Gymnocarpium ×brittonianum (Sarvela) Pryer & Haufler is a rare oak fern hybrid known from CT, MA, ME, NH, VT. Morphologically it most closely resembles G. disjunctum, with the first pair of leafules of the second pair of leaflets markedly unequal in length (the basiscopic leafules much longer than the acroscopic leafules; those of G. dryopteris are usually ± equal or the basiscopic leafules slightly longer). Spore morphology is an important character for diagnosing this hybrid. Both round and abortive spores are present. Distribution of this nothospecies is based on Pryer and Haufler (1993). Given that G. disjunctum is restricted to northwestern North America, it is plausible that plants seen with dimorphic spores are the result of a different hybrid combination or a separate phenomenon altogether.
Native to North America?
Yes
Synonyms
- Carpogymnia dryopteris (L.) A. & D. Löve
- Dryopteris dryopteris (L.) Britt.
- Polypodium dryopteris L.