GENUS 14. 



FERN FAMILY. 



14. ADIANTUM [Tourn.] L. Sp. PI. 1094. 1753. 



Graceful ferns of rocky hillsides, woods and ravines, with much divided leaves, the stipes 

 and branches slender or filiform, rigid, polished, usually dark-colored and shining. Sori 

 appearing marginal, borne at the ends of the free forking veins, on the under side of reflexed 

 indusiiform marginal lobes of the pinnules or segments. [Name ancient.] 



A genus of about 175 species, largely tropical American. Besides the following another occurs 

 in Florida, one in Texas and one in California and Nevada. Type species: A. Capillus-Veneris L. 

 Blades ovate-lanceolate in outline, with a continuous main rachis. i. A. Capillus-Veneris. 



Blades reniform-orbicular, the two equal divisions with pinnate branches. 2. A. pcdatum. 



i. Adiantum Capillus-Veneris L. 



Venus-hair Fern. Fig. 71. 

 Adiantum Capillus-Veneris L. Sp. PI. 1096. 1753- 



Rootstock creeping, rather slender, chaffy 

 with light-brown scales. Stipes very slender, 

 black, or nearly so and shining, 3'-i2' long; 

 blades ovate-lanceolate in outline, 2-pinnate 

 below, simply pinnate above, membranous, 

 6'-2 long, 4-12' wide at the base; pinnules 

 and upper pinnae wedge-obovate or rhomboid, 

 rather long-stalked, glabrous, the upper mar- 

 gin rounded and more or less deeply incised, 

 the sterile lobes crenate or dentate-serrate, the 

 fertile ones with lunate or transversely oblong 

 indusia ; main and secondary rachises and stalks 

 of the pinnules black or dark brown. 



In ravines, Virginia to Florida, west to Mis- 

 souri, Utah and California. Also in South Da- 

 kota. Ascends to 1300 ft. in Kentucky. Also in 

 tropical America, and in the warmer parts of the 

 Old World. June-Aug. True or black maiden's- 

 hair. Lady's-hair. Dudder-grass. 



2. Adiantum pedatum L. Maiden-hair 

 or Lock-hair Fern. Fig. 72. 



Adiantum pcdatum L. Sp. PI. 1095. 1753. 



Rootstock slender, creeping, chaffy, root- 

 ing along its whole length. Stipes g'-i8' 

 long, dark chestnut-brown, polished and shin- 

 ing, once forked at the summit ; blades reni- 

 form-orbicular in outline, 8'-i8' broad, mem- 

 branous, the pinnae arising from the outer 

 sides of the two equal branches, somewhat 

 pedately arranged, the larger ones 6'-io' long, 

 i '-2' wide; pinnules oblong, triangular-oblong, 

 or the terminal one fan-shaped, short-stalked, 

 the lower margin entire and slightly curved, 

 the upper margin cleft or lobed, the lobes 

 bearing the linear-oblong, often short sori. 



In woods. Nova Scotia and Quebec to Alaska, 

 south to Georgia, Louisiana, Kansas ; Rocky 

 Mountains to Utah and California. Ascends to 

 5000 ft. in Virginia. Also in Asia. July-Sept. 

 Most of the western and northwestern specimens 

 and from the Gaspe region, Quebec, are referable 

 to the var. aleuticum Rupr., characterized by its 

 fewer and more strict pinnae and more deeply 

 cleft pinnules and stouter suberect rootstock. 



15. PTERI'DIUM Scop. FI. Cam. 169. 1760. 



Coarse ferns of open or partially shaded situations, the triangular or deltoid-ovate com- 

 pound blades borne upon stout stipes, these scattered upon a slender freely branched woody 

 rootstock creeping underground. Sori in a continuous marginal line, arising from a trans- 

 verse vein-like receptacle connecting the ends of the forked free veins. Indusium double, the 

 outer conspicuous, formed by the reflexed membranous margin of the blade ; the inner 

 obscure, delicate, borne upon the receptacle. [Greek name for ferns.] 



Variously regarded as containing one or several species of the widest distribution, the several 

 forms closely allied to the following, the generic type. P. caudatum occurs in Florida. 



