Woodsia ilvensis — rusty cliff fern
![Plant form: Woodsia ilvensis. ~ By Arthur Haines. ~ Copyright © 2024 Arthur Haines. ~ arthur.d.haines[at]gmail.com](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Woodsiaceae/woodsia-ilvensis-ha-ahaines.jpg)
![Leaf: Woodsia ilvensis. ~ By Cheryl Lowe. ~ Copyright © 2024 New England Wild Flower Society. ~ Image Request, images[at]newenglandwild.org](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Woodsiaceae/woodsia-ilvensis-le-clowe.jpg)
![Detail of leaf and/or divisions: Woodsia ilvensis. ~ By Gordon Morrison. ~ Copyright © 2024 New England Wild Flower Society. ~ Image Request, images[at]newenglandwild.org](https://newfs.s3.amazonaws.com/taxon-images-1000s1000/Woodsiaceae/woodsia-ilvensis-ld-gmorrison.jpg)
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Facts
The silvery white undersides of rusty cliff fern's fronds turn a rusty color in the fall.
Habitat
Cliffs, balds, or ledges, ridges or ledges, 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.
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enlargeCharacteristics
- Habitat
- terrestrial
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Vermont
- Leaf divisions
-
- the leaf blade is compound (divided into leaflets)
- 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
- 5–15 cm
- Leaf vein tips
- the veins end in small round expanded areas, and do not reach 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
-
- the leaves are hairy, with hairs that branch into four branches near the tip
- there are no special features on the leaves
- Leaf blade length
- 5–15 cm
- Leaf blade shape
- the leaf blades are widest above the base, then taper narrowly towards the tip (lanceolate)
- Leaf blade tip shape
-
- the tip of the leaf blade is a sharp point (acute)
- the tip of the leaf blade is rounded
- Leaf blade width
- At least 1 cm
- Leaf divisions
-
- the leaf blade is compound (divided into leaflets)
- 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
- red or red-brown to purple or black
- Leaf stalk hairs
- the leaf stalk has hairs
- Leaf stalk length
- 17–125 mm
- Leaf stalk relative length
-
- the leaf stalk is more than a quarter, but less than three quarters as long as the blade
- the leaf stalk is more than three quarters as long as the blade
- Leaf stalk scale location
- the scales are present on both the lower and upper halves 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 branch dichotomously (two equal branches at each branch point)
- Leaf vein tips
- the veins end in small round expanded areas, and do not reach the edge of the leaf blade
- Leaflet relative size
- the bottom leaflets are about half as long as, to slightly longer than, the leaflets from the middle of the frond
- Leaflet stalks
- the leaflets do not have stalks
- Lobe or leaflet length
- 4–20 mm
- Lobe or leaflet pairs
- 7–23
- Lobe or leaflet shape
-
- the lobe or leaflet is roughly triangular with the stalk in the center of the narrowest side (narrow-triangular)
- the lobe or leaflet is roughly triangular with the stalk in the center of the widest side (broad-triangular)
- the lobe or leaflet is widest below the middle and broadly tapering at both ends; egg-shaped
- the lobe or leaflet is widest below the middle and tapering at both ends; lance-shaped
- Lobe or leaflet width
- 3–11 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
- ridges or ledges
- 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
Not classified
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
- widespread (S-rank: S5)
- Rhode Island
- historical (S-rank: SH), state historical (code: SH)
From Flora Novae Angliae dichotomous key
3. Woodsia ilvensis (L.) R. Br. N
rusty cliff fern. Acrostichum ilvense L. • CT, MA, ME, NH, RI, VT. Cliffs and talus slopes, including xeric substrates.
1×3. Woodsia alpina × Woodsia ilvensis → Woodsia ×gracilis (Lawson) Butters is a rare, abortive-spored hybrid known from ME, VT . Compared with W. alpina, this hybrid fern tends to be larger, with more hairs and scales, and with leaflets more divided and with more pairs of leafules (often more than 3). Compared with W. ilvensis, this nothospecies tends to be smaller, with fewer hairs and scales, and with leaflets less divided.
Native to North America?
Yes
Sometimes confused with
- Cheilanthes lanosa:
- sori located on the margin, covered by a false indusium, and petioles not articulated (vs. W. ilvenis, with sori not located on the margin, covered by an inferior indusium that disintegrates into filaments, and petioles articulated).
- Woodsia alpina:
- leaflets glabrous or nearly so on the abaxial surface, though scales may be present on the rachis and costae, the larger leaflets with 2 or 3 pairs of leafules, and indusium composed of few filaments (vs. W. ilvensis, with leaflets with scales on the abaxial surface, the larger leaflets with 4–7 pairs of leafules, and indusium composed of many filaments).
Synonyms
- Acrostichum ilvense L.