Cyrtomium fortunei var. fortunei
Stem scales brown, ovate to lanceolate with attenuate apices. Leaves to 90 cm. Pinnae dark green and not shiny adaxially, (8–) 10–25 pairs, lanceolate-attenuate, usually falcate, 5–9 cm, papery, sometimes with short, basal, acroscopic lobe, margins minutely crenulate-denticulate. Indusia pale-brown to tan, thin, shriveled at maturity. n = 2n = 123, apogamous.
Habitat: Brick or stone walls, clay banks, mesic ravines
Elevation: 0–100 m
Introduced; Ga., La., Miss., Oreg., S.C., Europe, Asia
Cyrtomium fortunei is native to east Asia and widely escaped from cultivation. Two other varieties, var. intermedium Tagawa and var. clivicola (Makino) Tagawa, occur in Asia. Cyrtomium caryotideum (Wallich ex Hooker & Greville) C. Presl is another commonly cultivated species of Asiatic holly fern. It is native in Hawaii, but it is not yet known to have become established outside of cultivation in the flora area. It is characterized by having only 3–5 pairs of pinnae, with finely and sharply serrulate margins.
"thin" is not a number.