OSMUNDACEAE. 



VOL. L 



3. Osmunda Claytoniana L. 

 Clayton's Fern. Fig. 17. 



Osmunda Claytoniana L. Sp. PI. 1066. 1753. 

 Osmunda interrupta Michx. Fl. Bor. Am. 2: 273. 

 1803. 



Rootstock stout, creeping; leaves 2-6 long, 

 loosely tomentose when young, glabrous with age, 

 the outer ones usually sterile and spreading, the 

 inner erect and usually fertile in the middle. 

 Blades oblong-lanceolate, i-4 long; sterile pinnae 

 oblong-lanceolate, deeply cleft into ovate-oblong 

 close or slightly imbricate segments, the margins 

 usually entire; fertile pinnae 2-5 pairs, fully pin- 

 nate, the cylindric divisions very close, greenish 

 at first, dark brown, brittle and withering with 

 age. 



In swamps and moist woods, Newfoundland to 

 Minnesota south to North Carolina, Kentucky and 

 Missouri. Ascends to 5000 ft. in Virginia. Also in 

 China and India. May-July. Interrupted- or Clay- 

 ton's-flowering-fern. 



Family 3. HYMENOPHYLLACEAE Gaud, in Freyc. Voy. 262. 



FILMY-FERN FAMILY. 



1826. 



Membranaceous, mostly tropical small ferns, with slender often filiform creep- 

 ing or rarely suberect rootstocks, the leaves usually much divided, the leaf-tissue 

 pellucid, usually of a single layer of cells. Sporanges sessile upon a filiform, 

 usually elongate receptacle, within an urn-shaped or tubular truncate or two- 

 lipped marginal indusium, terminal upon the veins; ring complete, transverse, 

 opening vertically. 



Two genera, Hymenophyllum and the following, comprising some 450 or more species, abun- 

 dant in the humid tropics and mainly epiphytic. 



i. TRICHOMANES L. Sp. PI. 1097. 1753. 



Blades entire, pinnatifid or lobed, or several times pinnately divided. Indusium tubular 

 or funnel-shaped, truncate or sometimes broadly two-lipped, the sporanges sessile, mostly 

 upon the lower portion of the slender often exserted receptacle. [Greek, in allusion to the 

 delicate hair-like ultimate segments of some of the species.] 



About 210 species, mostly tropical. Besides the following, 3 species occur in the southern 

 United States. Type species : Trichomanes crispum L. 



i. Trichomanes Boschianum Sturm. 

 Filmy-fern. Bristle-fern. Fig. 18. 



Trichomanes Boschianum Sturm ; v. d. Bosch, 



Ned. Kr. Arch. $ 2 : 160. 1861. 

 Trichomanes radicans of American writers. Not 



Sw. 



Rootstocks filiform, wiry, tomentose, creep- 

 ing. Stipes (petioles) ascending, i'~3' long, 

 naked or nearly so; blades 2'-8' long, 8"-ii' 

 wide, membranaceous, lanceolate or ovate- 

 lanceolate, 2-3-pinnatifid ; pinnae ovate, obtuse, 

 the upper side of the cuneate base parallel with 

 or appressed to the narrowly winged rachis; 

 segments toothed or cut into linear divisions ; 

 indusia terminal on short lobes, 1-4 on a pin- 

 nule, the mouth slightly 2-lipped ; receptacle 

 more or less exserted, bristle-like, bearing the 

 sessile sporanges mostly near the base. 



On wet rocks, Kentucky to Florida and Alabama. 



