?Amer. Fern J. 50: 107, 1960?. Submitted.

?Deutsche Bot. Monatsschr. 19: 93, 1901?. Submitted.

?Dist. Crypt. Vasc. Ross. 19, 1845?. Submitted.

?N?tt?rufræðingurinn 18: 101, 1948?. Submitted.

?Mem. Acad. Imp. Sci. St.-Petersbourg, Ser. 6, Sci. Math. 2: 174, 1832?. Submitted.

?Sp. Pl.  1062, 1753?. Submitted.

?Ann. Mus. Bot. Lugduno-Batavi 1: 69, 1863?. Submitted.

?Hannover. Mag. 1783: 286, 1783?. Submitted.

?Bot. Mag. (Tokyo) 39: 194, 1925?. Submitted.

?Contr. Lab. Bot. Univ. Montreal 9: 51, 1927?. Submitted.

?Fern Gaz. 11: 34, 1974?. Submitted.

?Enum. Pl. (Willdenow) 2: 1065, 1809?. Submitted.

?Sp. Pl. (ed. 5; Willdenow) 5: 8, 1810?. Submitted.

?Ann. Mus. Bot. Lugduno-Batavi 1: 62, 1863?. Submitted.

?Trans. Nat. Hist. Soc. Taiwan 20: 97, 1930?. Submitted.

?Bot. Mag. (Tokyo) 39: 159, 1925?. Submitted.

?Fern Bull. 12: 43, 1904?. Submitted.

?Deutschl. Fl. (Roehling) 3, 1795?. Submitted.

?Rhodora 20: 131, 1918?. Submitted.

?Amer. Fern J. 27: 58, 1937?. Submitted.

?Verh. K.K. Zool.-Bot. Ges. Wien 18: 758, 1868?. Submitted.

?Sp. Pl.  1060, 1753?. Submitted.

?Sp. Pl. 2: 1062, 1753?. Submitted.

?Sp. Pl.  1062, 1753?. Submitted.

?Sp. Pl.  1061, 1753?. Submitted.

?Hannover. Mag. 22: 138, 1784?. Submitted.

?Fl. Atlant. 2: 398, 1799?. Submitted.

?Fl. Bor.-Amer. (Michaux) 2: 281, 1803?. Submitted.

?Sp. Pl. 2: 1061, 1753?. Submitted.