Athyrium filix-femina in Flora of North America @ efloras.org

2. Athyrium filix-femina (Linnaeus) Roth, Tent. Fl. Germ. 3(1,1): 65. 1799 (as filix femina).

Lady fern, athyrie fougère-femelle

Polypodium filix-femina Linnaeus, Sp. Pl. 2: 1090. 1753 (as f. femina)

Stems short-creeping or ascending. Petiole straw-colored distally, 7--60 cm, base dark red-brown or black, swollen, with 2 rows of teeth; scales light to dark brown, linear- to ovate-lanceolate, 7--20 × 1--5 mm. Blade elliptic, lanceolate to oblanceolate, 2-pinnate to 2-pinnate-pinnatifid, 18--30 × 5--50 cm, herbaceous but with cartilaginous margin, narrowed to base, apex acuminate. Pinnae sessile to short-stalked, linear-oblong to lanceolate, apex acuminate. Pinnules pinnatifid, segments oblong-linear to narrowly deltate, margins serrate. Rachis , costae, and costules glabrous or with glands or hairs. Veins pinnate. Sori straight, hooked at distal end, or horseshoe-shaped; indusia dentate or ciliate.

Varieties ca. 5 (4 in the flora): North America, Mexico, Central America, South America, Europe, Asia.

Athyrium filix-femina is circumboreal, and this or closely related species extend into Mexico, Central America, and South America. The delimitation and infraspecific classification of A . filix-femina need detailed study.

1 Petiole scales more than 1 cm; blades ca. 2 times length of petioles, elliptic to oblanceolate. (2)

+ Petiole scales 1 cm or less; blades 1-1.5 times length of petioles, elliptic to lanceolate. (3)

2 (1) Pinnules narrowly deltate or oblong-lanceolate, nearly equilateral at base; indusia long-ciliate; spores yellow. 2a var. cyclosorum

+ Pinnules linear-oblong or linear-lanceolate, inequilateral at base; indusia dentate or long-ciliate; spores brown. 2b var. californicum

3 (1) Petiole scales brown to dark brown; blades elliptic, narrowed to base, broadest near or just below middle; pinnae sessile or short-stalked; pinnules linear to oblong; indusia not glandular; spores yellow. 2c var. angustum

+ Petiole scales light brown to brown; blades ovate-lanceolate to lanceolate, slightly narrowed to base, broadest just above base; pinnae usually stalked; pinnules oblong-lanceolate to narrowly deltate; indusia glandular or not; spores dark brown. 2d var. asplenioides

Lower Taxa