HYMENOPHYLLACEAE 3 



terminal ones elongated, 1-2 cm. long, the margins crenulate to sharply serrulate: 

 sporophyl very long-stalked, 3-4-pinnate: bud densely pilose, both portions bent in 

 vernation. [B. tenuifolium Underw.] 



In low woods and open places from New Brunswick to Minnesota, south to Florida. The 

 spores mature from August to October. 



3. Botxychium Alabam6nse Maxon. Leaves 2-3 dm. long, the common stalk 

 slender, 2-4 cm. long, hypogean; blade long- or short-stalked (averaging 2.5 cm.), 

 about 12 cm. long and broad, subpentagonal, tripinnate, ternately divided, the 

 divisions lax and usually long-stalked, the ultimate segments approximate or distant, 

 broadly obovate, 5-10 mm. broad, narrowly cuneate, adnate, chartaceous, the margins 

 fimbriate; panicle 2-3-pinnate, 7-10 cm. long, on stalks 10-15 cm. long. 



In open or partially shaded thickets, Alabama and Georgia. The spores mature in fall. 



4. Botrychium Virginianum (L.) Sw. Leaves 2-7 dm. high, the common 

 stalk slender, nearly all above ground, comprising i to § the length of the plant; 

 blade nearly or quite sessile, spreading, thin, deltoid, 1-4 dm. broad, nearly as long, 

 ternate, the short-stalked primary divisions pinnate or 2-pinnate, the segments 1-2- 

 pinnatifid; ultimate segments oblong, toothed at the apex; sporophyl long-stalked, 

 2-3-pinnate, with slender branches. 



In woods. Nova Scotia to British Columbia, Florida and Arizona. Also in Europe and 

 Asia, and in tropical America. Spring. 



Order 2. FILICALES. 



Terrestrial or epiphytic, or in one family aquatic, plants various in habit. 

 Sporanges developed normally from single epidermal cells, variously disposed, 

 mainly upon the under surface of the leaf, commonly in clusters (sori) upon 

 the veins, or within special marginal indusia, or, less commonly, irregularly or 

 in rows upon slender more or less non-foliose pinnae or segments. Spores of 

 one sort. Indusia of various form, or wanting. Prothallia flattish or fila- 

 mentous, green, terrestrial or epiphytic. 

 Leaves with filmy translucent blades: sporanges sessile on a filiform receptacle. 



Earn. 1. HYMENOPHYLLACEAE. 



Leaves with herbaceous or leathery blades: sporanges on normal or 



modified leaf-blades. 

 Sporanges in panicles or spikes. 



Sporanges nearly globose, with a rudimentary ring. _ Fam. 2. Osmundaceae. 



Sporanges ovoid or pyriform, with a complete apical ring. Fam. 3. Schizaeaceae. 

 Sporanges borne on the back or margin of a leaf-blade. 



Sporanges nearly sessile: plants aquatic or semiaquatic. Fam. 4. Ceratopteridaceae. 



Sporanges long-stalked: plants terrestrial or epiphytic. Fam. 5. Polypodiaceae. 



Family 1. HYMENOPHYLLACEAE Gaud. Filmy Feen Family. 



Membranous, mostly tropical small ferns with filiform or slender creeping 

 or suberect rootstoeks. Leaf -blades usually much divided, the leaf-tissue pel- 

 lucid, usually consisting of a single layer of cells. Sporanges sessile upon a 

 filiform usually elongated receptacle within an urn-shaped or tubular truncate 

 or 2-lipped marginal indusium which is terminal upon the vein; ring complete, 

 transverse, opening vertically. 



1. TRICHOMANES L. 



Leaf-blades entire, pinnatifid or lobed, or several times pinnately divided. 

 Indusium tubular or funnel-shaped, truncate or sometimes broadly 2-lipped, the 

 sporanges mostly upon the lower portion of the slender often exserted receptacle. 



Leaf-blades simple, the margins crenate or incised. 



Indusia solitary, terminal, slightly 2-lipped. 1. T. Petersii. 



Indusia several, strongly 2-lipped. 2. T. sphenodes. 

 Leaf-blades pinnatified to 3-pinnatifid. 



Leaf-blades 2 cm. long, or less: indusium strongly 2-lipped. 3. T. Krausii. 



Leaf-blades 5-20 cm. long: indusium slightly 2-lipped. 4. T. Boschianum . 



1. Trichomanes Petersii A. Gray. Eootstocks widely creeping. Leaves with 

 a few black hairs along the margins when young; blades ovate, linear-oblong or 

 spatulate, entire or crenate, 6-24 mm. long, 2-4 mm. wide, on slender petioles: indu- 

 sium solitary, terminal, mainly immersed, funnel-form, expanded at the mouth. 

 Under moist rocks, Georgia, Alabama and Mississippi. 



