Osmunda .] FILICES. 345 



12. HYMENOPHYLLUM. Sm. Filmy-fern. 



Sori marginal. Capsules upon a narrow receptacle, .within 

 a two-valved involucre, which is of the same texture as the 

 frond, opening above. Named from v^iy, a membrane, and 

 0i>XXot/, a leaf; an admirably characteristic appellation. 



1. H. Tunbridgense, Sm. Tunbridge Filmy-fern. Fronds 

 tender, pinnate ; pinnae distichous, vertical, pinnatifid, the seg- 

 ments linear, undivided or bifid, and as well as the axillary, 

 solitary, suborbicular compressed involucre, spinuloso-serrate ; 

 rachis strongly winged. Br. Fl. ed. 3. p. 456. E. Bot. t. 162. 

 Hook, in Fl. Land. N. S. t. 71. E. Fl. v. iv.p. 327. 



Moist rocks in mountainous situations. Powerscourt Waterfall, 

 Glencree and other places in the County of Wicklow, and many other 

 parts of the country. Habit tender and delicate, spreading widely over 

 the rocks on which it grows. PinncB pointing 1 in two opposite direc- 

 tions, flat and vertical, on the same plane with the winged rachis. 

 Involucres nearly orbicular, slightly swollen at the base, where the clus- 

 ter of capsules is lodged, the rest compressed, especially at the margin 

 of the valves. When dry there is a kind of elasticity in the plant. 



2. H. Wilsoni, Hook. Scottish Filmy-fern. Fronds rigid, 

 pinnate ; pinnae recurved, subunilateral, pinnatifid, the segments 

 linear, undivided or bifid, spinuloso-serrate ; involucres axil- 

 lary, solitary, ovate, inflated, entire; rachis only slightly mar- 

 gined towards the extremity. Br. Fl. ed. 3. p. 456. Wilson 

 in E. Bot. Suppl. t. 2686. 



On wet shaded rocks, generally in elevated situations in many parts 

 of the country. On the Kerry mountains, Cunnamara, and Glencree, 

 County of Wicklow. On Sugar-loaf Mountain ; Mr. NuttalL First 

 distinguished as a species distinct from H. Tunbridgense by Mr. W. 

 Wilson, who found it near Killarney. " More rigid, and with larger 

 reticulations than the last ; quite distinct in its mode of growth, for all 

 the pinncB are strongly curved backwards, in a direction contrary to 

 that of the fructification : the involucre is totally different, larger, 

 browner, of a more rigid texture, truly ovate, each valve remarkably 

 convex for its whole length, the edges only of the valves being applied 

 to each other, and they are quite entire." Hook. 



% s| Capsules spiked or clustered, regularly 2-valved, without 

 an elastic jointed ring. (OSMUNDACE.E and OPHIOGLOSSE^, Br.) 



13. OSMUNDA. Linn. Osmund-royal, or Flowering-fern. 



Capsules subglobose, pedicellate, clustered, striated, half two- 

 valved. Involucre none. Name, probably given, as Sir J. 

 E. Smith suggests, in honour of some person. Osmund, in 

 Saxon, is said to mean domestic peace. 



1. O. regalis, Linn. Common Osmund-royal. Fronds bi- 



u u 



