Adiantum viridimontanum — Green Mountain maidenhair fern
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New England distribution
Adapted from BONAP data
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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Green Mountain maidenhair fern is a rare endemic found only in northern Vermont and Maine, and southern Quebec. It inhabits steep cliffs, talus slopes, and thin soils of woodlands and forest edges, on serpentine bedrock. Unlike other globally rare species, its populations appear relatively stable (at least up to 2001). The greatest threats to this species are mining, road building, over-collection, logging and development.
Cliffs, balds, or ledges, forest edges, forests, ridges or ledges, talus and rocky slopes
- New England state
- Features of leaves
- the petiole (leaf stalk or stipe) appears to fork into two equal halves
- New England state
- Specific habitat
- cliffs, balds, or ledges
- edges of forests
- ridges or ledges
- talus or rocky slopes
New England distribution and conservation status
- New Hampshire
- Rhode Island
Exact status definitions can vary from state to state. For details, please check with your state.
- rare (S-rank: S2), threatened (code: T)
Native to North America?
Sometimes confused with
- Adiantum aleuticum:
- ultimate leaf segments on stalks 0.3-1.3 mm long and false indusial 0.8-2.9 (rarely to 3.4) mm long (vs. A. viridimontanum, with ultimate leaf segments on stalks longer than 0.9 mm and false indusial 2-5 (rarely to 10) mm long).
- Adiantum pedatum:
- ultimate leaf segments oblong, rounded at the apex, in plane with the blade axis and plants of rich soils (vs. A. viridimontanum, with ultimate leaf segments +/- triangular, acute to obtuse at the apex, often twisted out of plane with the blade axis and plants of serpentine soils).
From the dichotomous key of Flora Novae Angliae
3. Adiantum viridimontanum Paris NC
Green Mountain maidenhair fern. ME, VT. Serpentine cliffs and talus, thin soil of woodlands and forest edges on serpentine bedrock.