POLYPODIACEAE. 469 



9. ASPLENIUM L. Sp. PI. 1078. 1753. 



Large or small ferns with entire lobed pinnate, 2-3-pinnate, or pinnatifid 

 leaves, and linear or oblong sori oblique to the midribs or rachises. Leaves 

 mostly uniform. Veins free. Indusia straight or curved, opening toward the 

 midribs. [Ancient Greek name; some species were supposed to be remedies 

 for diseases of the spleen.] A genus of some 400 species, of very wide 

 geographical distribution. Type species: Asplenium Trichomanes L. 



1. Asplenium dentatum L. Sp. PI. 1080. 1753. 



Petioles tufted, 5-15 cm. long, naked, weak, blackish below. Fertile leaf- 

 blades 5-12 em. long, with 6-8 pairs of stalked oblong or rhombic pinnae, the 

 lower side truncate with a curve, the outer edge irregularly crenate; sterile 

 leaves similar but with shorter petioles; rachis naked; sori copious. 



In a cave, New Providence : in a deep sink-hole, Cat Island : Florida ; Bermuda ; 

 Jamaica ; Cuba ; Hispaniola ; Guadelope : Barbados ; Mexico and Central America. 

 TOOTHED SPLEEXWORT. 



Sehoepf records observing Asplenium rhizopJiyllum L., and A. marinum L., on 

 New Providence in 1784 ; we do not know what ferns he had in mind. 



10. PITYKOGRAMMA Link, Handb. 3: 19. 1833. 



Terrestrial ferns, with tufted, mostly bipinnate leaves, usually white- 

 powdery or yellow-powdery on the under side, the sori dorsal, linear along the 

 veins, nearly confluent. Indusia wanting. [Greek, bran-fern, with reference 

 to the powdery under leaf -surfaces.] Ten species, or more, natives of tropical 

 and subtropical regions. Type species: Acrostichum chrysopliyllum Sw. 



1. Pityrogramma calomelanos (L.) Link, Handb. 3: 19. 1833. 



Acrostichum calomelanos L. Sp. PI. 1072. 1753. 

 Gymnofiramme calomelanos Kaulf. Enum>. Fil. 76. 1824. 

 Neurogramme calomelanos Diels in E. & P. Nat. Pfl. I 4 : 264. 1899. 



Eootstock short, rather s-tout, erect or nearly so. Leaves tufted, erect or 

 arching, ovate to ovate-lanceolate in outline, 2-pinnate, 2-8 dm. long, the dark 

 brown shining petiole usually shorter than the blade; rachis dark brown, 

 shining; pinnae lanceolate, acuminate, usually white-pulverulent beneath; 

 pinnules lanceolate, acute or acuminate, dentate or entire, chartaceous, deeur- 

 rent, the upper commonly confluent. 



Sink-hole. Smith Hill Coppice, Andros : West Indies ; continental tropical 

 America. SILVER-FERX. 



11. POLYPODIUM [Tourn.] L. Sp. PI. 1082. 1753. 



Pinnate or simple ferns with stipes articulated to the creeping rootstocks. 

 Sori hemispheric, dorsal, in one or more rows on either side of the midribs. 

 Indusium none. Veins free or variously anastomosing. [Greek, in allusion to 

 the knob-like prominences on the rootstocks of some species.] About 350 species, 

 of wide distribution, mostly tropical. Type species: Polypodium vulgare L. 



Rootstocks slender, wide-creeping, the leaves distant ; sori 



deeply impressed. 1. P. poli/podioides. 



Rootstocks thicker, short-creeping, the leaves approximate ; 



sori superficial. 2. P. sqiiamatum. 



