A. aleuticum typically grows about 18-30 inches tall and wide. The
fronds grow tall, and are fan-shaped, light to medium green with dark brown to black stems. When growing in relative shade, fronds are held horizontally, but it also can grow in high mountains in full sun (often on serpentine rock) with fronds held vertically. New fronds unfurl from a tight coil (
circinate vernation) held on a tall stalk. Oblong
sori (masses of spores) form beneath a curled-under leaflet edge (
false indusium). H20150408-0024—Adiantum aleuticum—RPBG (17192418876).jpg|Tilden Regional Park California Adiantum aleuticum subsp. calderi - Flickr - brewbooks.jpg|growing on serpentine rock Adiantum aleuticum JHT iNat199860221.jpg| ==Taxonomy==