18 



POLYPODIACEAE 



and succulent ; pinnae or segments articulate or not, entire to variously incised or cleft. Sori 

 oblong to narrowly linear, borne upon the free, usually oblique ultimate veins, usually below 

 their tip ; indusia invariably present, lateral, oblong to narrowly linear, usually membranous, 

 often concealed by the sporangia at maturity. [Ancient Greek name, being a supposed 

 remedy for the spleen.] 



Nearly 600 species, mainly of tropical and subtropical regions of both hemispheres. Besides the follow- 

 ing about 20 species occur in the United States, mainly in Florida and the Appalachian region. Type 

 species, Asplenimn trichoinancs L. 



Stipe and rachis dark castaneous or purplish brown throughout, glossy. 



Rachis narrowly yellowish-alate, naked; pinnae crenulate or shallowly crenate, not aunculate; veins 

 mostly forked. 1- A. trichoinancs. 



Rachis not alate, deciduously fibrillose with tortuous, brown, gland-tipped hairs; pinnae deeply and 

 obliquely crenate, subauriculate; veins mostly simple. 2. A. vesfcrtinum. 



Stipe reddish brown below, the upper part and the rachis green. 3. A. I'in'de. 



1. Asplenium trichomanes L. 

 Maidenhair Spleenwort. Fig. 34. 



Asplenium trichomanes L. Sp. PI. 1080. 1753. 



Rhizome erect or decumbent, 1-2 cm. long. 5-10 mm. in 

 diameter, paleaceous at the exposed apex ; scales linear-atten- 

 uate, up to 4.5 mm. long, with a narrow, dark brown median 

 stripe. Fronds numerous, wide-spreading, 5-26 cm. long; stipes 

 1-5 cm. long, arcuate, like the rachis dark castaneous to purplish 

 brown, lustrous, glabrous ; blades narrowly linear, 4-21 cm. long, 

 5-15 mm. broad, narrowed downward, once pinnate, the rachis 

 narrowly yellowish-alate above; pinnae 15-35 pairs, opposite to 

 alternate, the lower ones distant, roundish-deltoid or fan-shaped, 

 those above closer, oval to broadly oblong from a broadly cuneate 

 to subrectangular base, mostly inequilateral, crenulate or shallow- 

 L ly crenate ; veins mostly once forked ; sori 3-5 pairs, linear-oblong, 

 medial; indusia ample, subentire ; leaf tissue bright green, 

 herbaceous, evergreen. 



Crevices of cliffs, usually limestone, chiefly in the Transition and Ca- 

 nadian Zones; Alaska and the Hudson's Bay region to Nova Scotia, south 

 in the mountains to Oregon, the Mexican Border states, Alabama, and 

 Georgia. Type locality, European. 



2. Asplenium vespertinum Alaxon. 



Western Spleenwort. Fig. 35. 



Asplenium vespertinum Maxon, Bull. Torrey Club 27: 197. 1900. 

 Rhizome erect or ascending, 1-2 cm. long, rather 

 stout; scales linear-acicular, 2-2.5 mm. long, dark brown, 

 rigid. Fronds numerous, closely fasciculate, arcuately 

 ascending, 5-24 cm. long; stipes 1-4 cm. long, stout, 

 purplish brown, lustrous, with a few blackish gland- 

 tipped fibrils ; blades linear or oblanceolate-linear, 4-20 

 cm. long, 1-2.5 cm. broad, once pinnate, the rachis 

 brown, sulcate above, deciduously fibrillose ; pinnae 

 20-30 pairs, subopposite to alternate, the lower ones dis- 

 tant, reduced, short-stalked, reflexed, those above 

 closer, sessile, horizontal, oblong or linear-oblong from 

 an inequilateral, broadly cuneate or rectangular base, 

 subauriculate, deeply and obliquely crenate, the veins 

 (except in the basal lobe) simple; sori 4-6 pairs, short, 

 infra-medial ; indusia narrow, firm, crenulate ; leaf 

 tissue light or yellowish green, herbaceous. 



Moist crevices beneath overhanging rocks. Upper Sonoran 

 Zone; San Gabriel Mountains (Los Angeles County) to the vicin- 

 ity of San Bernardino, California, southward on the seaward 

 side of the mountains into Lower California. Type locality: Na- 

 tional City, .San Dieeo County, California. 



