FERN FAMILY 



19 



3. Asplenium viride Huds. 

 Green Spleenwort. Fig. 36. 



Asflcnium riride Huds. Fl. Angl. 385. 1762. 



Plants tufted, the rhizomes creeping, 2-10 cm. long; 

 scales linear-attenuate, up to 3.5 mm. long, brown, con- 

 colorous or with a dark brown basal stripe. Fronds numer- 

 ous, tufted. 3-20 cm. long, laxly ascending; stipes 1-7 cm. 

 long, weak, stramineous to green above the reddish brown 

 base, scantily fibrillose ; blades narrowly linear-lanceolate 

 to oblong-linear, 2-14 cm. long, 5-15 mm. broad, attenuate, 

 once pinnate, the delicate green rachis slightly fibrillose ; 

 pinnae 5-25 pairs, the lower ones usually distant, broadly 

 rounded-deltoid, opposite, those above closer, becoming 

 alternate, rhombic to rhombic-oblong or obliquely ovate, ^. 

 obtuse, stalked, broadly cuneate at the inequilateral base, 

 crenate to crenately lolied ; basal veins forked, the others 

 forked or simple ; sori 2-4 pairs, remote from the margin, 

 soon confluent and concealing the delicate, subentire in- 

 dusia ; leaf tissue bright or yellowish green, soft-herba- 

 ceous, glabrous. 



Crevices of shaded cliffs, Hudsoniaii Zone; Alaska to Newfound- 

 land, south in the mountains to Oregon, Wyoming, and Vermont; 

 also in Eurasia. Type locality, European. 



8. ATHYRIUM Roth, Rom. Arch. Bot. 2^ : 105. 1799. 



Medium-sized to large ferns of upright habit, usually growing in moist shaded situa- 

 tions, the rhizomes creeping (often slender) to oblique and densely tufted; rhizome scales 

 membranous, with thin-walled cells. Fronds usually large, erect-spreading, long-stipitate, 

 or the stipe nearly wanting ; blades ample, usually elongate, 1-3-pinnate, the segments sub- 

 entire to incised or pinnatifid, membranous to herbaceous ; veins free. Sori dorsal, oblique 

 to the midrib, narrowly oblong, or commonly crossing the vein and recurved, becoming lunate, 

 hippocrepiform, or (rarely) roundish; indusia shaped like the sori, attached along the inner 

 side, facing outward, subentire to fimbriate, delicate, sometimes minute and hidden, rarely 

 wanting. [Name Greek, meaning shieldless, of doubtful application.] 



About ISO species, mainly of tropical regions. Four additional species occur in eastern North Amer- 

 ica. Type species, Polypodium filix-fonina L. 



Blades ample, foliose, the segments mostly close; indusia oblong to lunate or hippocrepiform, fringed with 

 "septate cilia. 1- A. filix-femina. 



Blades skeleton-like, the segments very narrow, oblique, distant; indusia wanting, the sorus roundish. 



2. A. americanum. 



1. Athyrium filix-femina (L.) Roth. 

 Lady-fern. Fig. Z7. 



Polvtodium filix-femina L. Sp. PI. 1090. 1753. 



Athyrium filix-femina Roth, Rom. Arch. Bot. 2': 106. 1799. 



Asplenium filix-femina Bernh. Schrad. Neues Journ. Bot. 1": 



26. 1806. 

 y Athyrium cxclosorum Rupr. Beitr. Pflanzenk. Russ. Reich. 



3: 41. 1845. 

 5 Athyrium sitchense Rupr. Beitr. Pflanzenk. Russ. Reich. 3: 



41." 1845. 

 Athyrium filix-femina calif ornicum Butters, Rhodora 19: 201. 



1918. 



Rhizome erect or ascending, stout, paleaceous, the 

 scales lanceolate, up to 1 cm. long, light to dark 

 brown, thin. Fronds up to 2 meters long, erect- 

 arching ; stipes short, stramineous, paleaceous at 

 the dark base ; blades lanceolate, attenuate in both 

 directions (the lower pinnae distant), 2-3-pinnate; 

 pinnae linear to lance-oblong, acuminate to atten- 

 uate, sessile, obliquely spreading; segments crenate, 

 variously incised, or pinnatifid, membranous, gla- 

 brous or minutely glandular; sori usually less than 

 1 mm. long, oblong to lunate or hippocrepiform; 

 indusia sometimes toothed, septate-ciliate. 



Forests, moist thickets, and open or l>rushy slopes. Transi- 

 tion and Canadian Zones; Alaska to southern California and 

 in the Rocky Mountains to Nevada and New Mexico; Eurasia. 

 Type locality, European. 



