HYMENOPHYLLUM. 



13 



GENUS L 



HYMENOPHYLLUM. Smith. 



A group of dwarf Ferns, for the most part more resembling 

 mosses than Ferns, two of which, H. Twibridgense and H 

 unilaterale, are natives of Great Britain. They are all difficult 

 to cultivate, which renders the foreign species rare in a living 

 state in this country. 



The fronds are pellucid, membranaceous, simple, or decom- 

 pound, with a creeping and mostly filiform rhizoma. 



Sori situated within a two-valved involucre. 



Veins dichotomously branched, being simple and costseform 

 in the segments. 



The name is derived from the Greek, hymen — a membrane, 

 and phyllon — a leaf. 



Known in England as the "Film Fern," or "Filmy Fern." 



Sir W. J. Hooker gives eighty-five species in his "Species 

 Filicum," namely, — 



Omentum, Cavanilles, Chiloe. 



Marginatum, Hooker, New 

 Holland. 



Asplenioides, Sivartz, Jamaica. 



Abruptum, Hooker, Jamaica. 



Hirsutum, Swartz, Jamaica. 



Ciliatum, Swartz, West Indies. 



Plumieri, Hooker, Hispaniola. 



Trichophyllum, Hooker, Cumana 



Boryanum, JVilldenow, Mauritius 



Hirteilum, Swartz, Jamaica. 



Chiloense, Hooker, Chiloe. 



Organense, Hooker, Brazil. 



Valvatum, Hooker, Columbia. 



Beyrichianum, Kunze, Peru. 



Microcarpum? Desvaux, His- 

 paniola. 



Capillare? Desvaux. 

 Elegans, Sprengel, Brazil. 

 Pulchellum, Schleclitendal, 



Mexico. 

 Sericeum, Sivartz, Jamaica. 

 Interruptum, Kunze, Pampayaco 

 Pyramidatum, Desvaux, Tropi- 



ical America. 

 Elasticum, Bory, Mauritius. 

 Berteroi, Hooker, Juan Fer- 



nandes. 

 Obtusum, Hooker, Oahu. 

 iEruginosum, Carmichael, New 



Zealand. 

 Lanceolatum, Hooker, Oahu. 

 Lindeni, Hooker, Caraccas. 

 Arbuscula? Desvaux, Mauritius. 



