IlYMENOrHYLLUM.] FILICES. 509 



1. HYMENOPHYL'LUM, Sm. FlLMY-FERN. 



Rootstock filiform, creeping. Fronds usually matted and 2-4-pinnatifid 

 or -pinnate, pellucid, reticulate ; segments with a midrib ; veins 0. Sort 

 marginal, axillary or terminal ; involucre free or sunk in the frond, 

 2-valved or 2-lipped, opening outwards ; capsules sessile on a columnar 

 receptacle; ring complete, oblique. — Distrib. Trop. and temp, 

 regions ; species 70. — Etym. vfiijv and <pvX\ov, from the membranous 

 fronds. 



1. H. tunbridgen'se, Sm. ; frond ovate pinnate below, pinnatifid 

 above, pinna? spreading spinulose-serrate, involucre toothed. 



Moist shaded rocks or copses, from Stirling, Mull, and Argyll southd. to W. 

 York, and from Kent to Cornwall (ascending to 1,000 ft.) ; Ireland, rare ; 

 Channel Islands ; frt. June-July. — Rootstocks capillary, interlaced. Stipes 

 1-2 in-, winged above. Frond 1-3 in., glabrous ; pinnae distichous, flabel- 

 lately pinnatifid, lobes linear ; involucre solitary, axillary, suborbicular, lips 

 strongly irregularly toothed.— Distrib. Belgium, France, Germany, Italy, 

 Canaries, S. temp, regions. 



2. H. unilatera'le, Willd. ; frond oblong pinnate below or through- 

 out, pinnules, decurved spinulose-serrate, involucre entire. H. Wilso'ni, 

 Hook. 



Moist shaded rocks or copses, Shetland to York; Stafford, Salop, Wales, 

 Devon, Cornwall ; ascends to 2,800 ft. in the Hebrides, and 2,400 in 

 Ireland ; frt. June-July. -Perhaps only a sub-species of H. tunbridyerise, 

 h\xt more rigid, darker green ; involucre more ovoid and turgid ; pinna? 

 pinnatifid chiefly on the upper side. — Distrib. As H. tunbridgen'se. 



2. TRICHOM'ANES, L. Bristle-Fern. 



Rootstock creeping or tufted, stout or slender. Frond erect or pendu- 

 lous, simple pinnate or 1-4-pinnatifid, usually pellucid, reticulate ; 

 segments with a stout simple or forked midrib. Sori marginal, axillary 

 or terminal ; involucre elongate, free or sunk in the frond, tubular or 

 campanulate, mouth entire or 2-lipped, opening outwards ; capsules sessile 

 on a long often exserted receptacle. — Distrib. Chiefly trop. and damp 

 warm climates ; species 78. — Etym. obscure. 



T. radi'cans, Sw. ; rootstock creeping, frond 2-3-pinnatifid. T. 

 specio'sum, Willd. 



Wet shaded rocks, Killarney, York, S. Wales, Argyll, Arran ; frt. July-Sept.— 

 Rootstock slender, wiry, extensively creeping, tomentose. Stipes 2-6 in., 

 stout, wiry, ascending, naked below, winged above. Frond 4-12 in., mem- 

 branous, firm; rachis winged; lower pinnae 1-4 in., rhomboid-ovate; pin- 

 nules the same shape, pinnatifid, toothed, nerves 1 to each segment. Sort 

 lateral, 1-4 to each pinnule ; tube of involucre short, lips small ; receptacle 

 exserted. — Distrib. W. Europe, trop. Africa and America, Himalaya, 

 Japan, Polynesia. 



