Adiantum viridimontanum
Green Mountain maidenhair | |
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Adiantum viridimontanum growing in a dunite roadcut | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Division: | Polypodiophyta |
Class: | Polypodiopsida |
Order: | Polypodiales |
Family: | Pteridaceae |
Genus: | Adiantum |
Species: | A. viridimontanum
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Binomial name | |
Adiantum viridimontanum C.A.Paris
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Synonyms | |
Adiantum pedatum subsp. viridimontanum (C.A.Paris) Fraser-Jenk. |
Adiantum viridimontanum, commonly known as Green Mountain maidenhair fern, is a
Until 1991, A. viridimontanum was grouped with the western maidenhair fern,
A. viridimontanum is difficult to distinguish from its parent species in the field. It can generally be separated from A. pedatum by the shape of the ultimate segments (the smallest divisions of the leaf), and by its habitat on thin, exposed serpentine soils rather than in rich woodlands. It more closely resembles A. aleuticum; but the stalks of the ultimate segments and the false indusia are longer and the spores larger.
Due to its limited distribution and similarity to other Adiantum species within its range, little is known of its ecology. It thrives on sunny, disturbed areas where
Description
Adiantum viridimontanum is a medium-sized,
However, this interpretation of the frond architecture (
The
The ultimate segments of the divided blade (the apparent "pinnules") are borne on short, dark stalks of 0.6 to 1.5 mm, with the dark color often spreading into the base of each segment. They are long and obliquely triangular, the
The
Identification
Adiantum viridimontanum closely resembles the other species in the A. pedatum complex (A. pedatum and A. aleuticum), and distinguishing the three in the field is difficult. Paris and Windham, in their study of the complex, noted that while each species, collectively, can be distinguished from the others, no single
One potentially distinguishing character is the shape of the ultimate segments in the middle part of the leaf blade, which are oblong in A. pedatum and long-triangular or reniform (kidney-shaped) in A. viridimontanum and some specimens of A. aleuticum. Furthermore, A. viridimontanum can grow in both shade and sun, while A. pedatum grows in shade only.[2]
Adiantum viridimontanum can be separated from the morphologically similar individuals of A. aleuticum by the greater length of the stalks on the medial ultimate segments and of the false indusia, measuring greater than 0.9 mm and greater than 3.5 mm, respectively, in A. viridimontanum. Spore size is also a useful character (although not easily measured in the field); the average A. viridimontanum spore measures 51.4 μm in diameter. While A. aleuticum spores can reach up to 53 μm, they average about 43 μm. In A. aleuticum growing as a disjunct on eastern serpentine (the specimens most likely to be confused with A. viridimontanum), the rhizome is much more frequently branched, with intervals of 1.0 to 2.0 mm between nodes.[2]
Taxonomy
The work which led to the recognition of Adiantum viridimontanum as a distinct taxon began in the early 20th century. Following the discovery of disjunct specimens of
From 1983 to 1985, Cathy A. Paris, then a graduate student, gathered specimens of A. pedatum from non-serpentine soils in the Midwest and Vermont, and from serpentine soils in New England and Canada, for
In 2015, Christopher Fraser-Jenkins treated it as a subspecies of a broadly defined A. pedatum as A. pedatum subsp. viridimontanum, arguing that the morphological similarity among members of the complex should outweigh the
Distribution and habitat
Adiantum viridimontanum is narrowly distributed in New England and Quebec. At least seven stations in Vermont lie in the Missisquoi Valley, in the northern Green Mountains, giving the fern its common name. The ultramafic rocks of this area extend northwards into Quebec, where as of 2001, eight stations were known in southern Quebec and six in the Thetford Mines area.[16] It is also known from one station on serpentine on Deer Isle, Maine.[17][18]
The fern thrives in thin serpentine soils on sunny, disturbed habitats such as roadcuts and talus slopes, in
The eastern serpentine outcrops where A. viridimontanum thrives have relatively few
Ecology
Adiantum viridimontanum largely
Little is known about the role of A. viridimontanum in the ecosystem. In general, ferns are less susceptible to
Conservation
Under the NatureServe conservation status system, A. viridimontanum is considered globally vulnerable (G3). It is considered critically imperiled (S1) in Maine,[21] imperiled (S2) in Vermont and vulnerable (S3) in Quebec.[1]
Notes and references
References
- ^ a b NatureServe 2023.
- ^ a b c d e f g h i Paris 1991.
- ^ Cullina 2008, pp. 31–33.
- ^ Cobb, Farnsworth & Lowe 2004, pp. 56–58.
- ^ Gleason & Cronquist 2009, p. 16.
- ^ Paris 1993.
- ^ a b Paris & Windham 1988.
- ^ a b c Ruesink 2001, p. 3.
- ^ Fernald 1905.
- ^ Jolley 1922.
- ^ Cody 1983.
- ^ Zika & Dann 1985.
- ^ Dann 1988, pp. 100–105.
- ^ Lu et al. 2011.
- ^ Fraser-Jenkins, Kandel & Pariyar 2015, p. 213.
- ^ Ruesink 2001, p. 1.
- ^ a b Harris & Rajakaruna 2009.
- ^ Rajakaruna & Boyd 2009.
- ^ Ruesink 2001, pp. 3–5.
- ^ Southgate, Patel & Barrington 2019.
- ^ MaineRarePlant 2021.
- ^ Ruesink 2001, pp. 4–5.
- ^ Cullina 2008, p. 33.
Works cited
- Cobb, Boughton; Farnsworth, Elizabeth; Lowe, Cheryl (2004). A Field Guide to Ferns of Northeastern and Central North America. Peterson Field Guides. New York: Houghton Mifflin. ISBN 0-618-39406-0.
- Cody, William J. (January 1983). "Adiantum pedatum ssp. calderi, a new subspecies in northeastern North America". JSTOR 23311123.
- Cullina, William (2008). Native Ferns, Moss & Grasses. New York: Houghton Mifflin. ISBN 978-0-618-53118-9.
- JSTOR 23293670.
- Fraser-Jenkins, Christopher R.; Kandel, Dhan Raj; Pariyar, Sagun (2015). Ferns and Fern-Allies of Nepal. Kathmandu: National Herbarium and Plant Laboratories, Department of Plant Resources, Ministry of Forests and Soil Conservation. ISBN 978-9937-2-9496-6.
- ISBN 978-0-89327-365-1.
- Dann, Kevin T. (1988). Traces on the Appalachians: A Natural History of Serpentine in Eastern North America. New Brunswick, New Jersey: Rutgers University Press. OCLC 17383706.
- Harris, Tanner B.; Rajakaruna, Nishanta (2009). "Adiantum viridimontanum, Aspidotis densa, Minuartia marcesens, and Symphyotrichum rhiannon: additional serpentine endemics from eastern North America" (PDF). Northeastern Naturalist. 16 (special issue 5): 111–120. S2CID 54871497.
- Jolley, L. Frances (October 1922). "A variety of maidenhair fern new to Vermont". Joint Bulletin of the Vermont Botanical and Bird Clubs (8): 40–41.
- Lu, Jin-Mei; Li, De-Zhu; Lutz, Sue; Soejima, Akiko; Yi, Tingshuang; Wen, Jun (2011). "Biogeographic disjunction between eastern Asia and North America in the Adiantum pedatum complex (Pteridaceae)". PMID 21965133.
- "Maine Rare Plant List". Maine Department of Agriculture, Conservation and Forestry. 2021. Retrieved September 24, 2023.
- "Adiantum viridimontanum". NatureServe. September 1, 2023. Retrieved September 24, 2023.
- Paris, Cathy A. (April 1991). "Adiantum viridimontanum, a new maidenhair fern in eastern North America". Rhodora. 93 (874): 105–121. JSTOR 23312786.
- Paris, Cathy A. (1993). "Adiantum". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico. Vol. 2: Pteridophytes and Gymnosperms. New York and Oxford: Oxford University Press. Retrieved October 30, 2011.
- Paris, Cathy A.; Windham, Michael D. (1988). "A biosystematic investigation of the Adiantum pedatum complex in eastern North America". JSTOR 2419103.
- Rajakaruna, Nishanta; Boyd, Robert S. (2009). "Advances in serpentine geoecology: a retrospective" (PDF). Northeastern Naturalist. 16 (special issue 5): 3. S2CID 59356565.
- Ruesink, Ana (2001). "Adiantum viridimontanum Paris (Green Mountain Maidenhair Fern) Conservation and Research Plan" (PDF). New England Wild Flower Society.
- Southgate, Morgan W.; Patel, Nikisha R.; Barrington, David S. (2019). "Ecological outcome of allopolyploidy in Adiantum (Pteridaceae): niche intermediacy and expansion into novel habitats". Rhodora. 121 (986): 108–135. S2CID 199639192.
- Zika, Peter F.; Dann, Kevin T. (July 1985). "Rare plants on ultramafic soils in Vermont". Rhodora. 87 (851): 293–304. JSTOR 23314548.