Adiantum aleuticum (Rupr.) Paris
Aleutian Maidenhair Fern
Habitat: On serpentine or other magnesian rock or magnesian limestone, ascending to subalpine areas. [Rocky summits and outcrops (non-forested, upland)]
Range: Limited to serpentine areas of western Newfoundland, Gaspe, Quebec, Northern New England; also disjunct populations in California and Washington.
Aids to Identification: Maidenhair ferns have thin, delicate leaflets on shiny black stems, with the sori forming on veins under the reflexed lobe margins. The aleutian maidenhair can be distinguished from northern maidenhair fern (Adiantum pedatum L.) by having stiffer, more erect leaves, more angular distal lobes on the leaf segments, and deeper sinuses. A. pedatum also grows in non-serpentine habitats.
Ecological characteristics: Ecological relationships in Maine are not well known. In Maine, it grows on bare rock patches among spruce krummholz.
Synonyms: Adiantum pedatum L. var. aleuticum Rupr.; Adiantum pedatum L. ssp. aleuticum (Rupr.) Calder & Taylor; and Adiantum pedatum L. ssp. calderi Cody.
Known Distribution in Maine: This rare plant has been documented from a total of 1 town(s) in the following county(ies): Franklin.
Reason(s) for rarity: Habitat naturally scarce.
Conservation considerations: The single known population is well established and in a remote location where it is not particularly vulnerable to human activities.