5 50 Filices Nephr odium. 



forming a short stem above ground. Stipes short. Pinnules 

 oblong, more or less toothed. Sori large, in one row on each 

 side of the costa. There are several varieties, differing in the 

 size and division of the frond and the quantity of chaffy scales 

 on the stipes and rachis. N. Borreri, N. abbreviatum, N. 

 tiffine, and N. cristatum, of Swartz, not of Eichard, are forms of 

 this species, in addition to which there are several crested and 

 proliferous varieties in cultivation. A widely-dispersed species. 

 N. cristatum differs from the foregoing in its flat, not 

 convex indusium, and in the broad base of the pinnules ; and 

 N. rigidum in its mucronate rigid pinnules. Both are com- 

 paratively rare in Britain. 



2. N. spinulbsum, including N. dilatatum^ etc. This is 

 another common species, usually affecting moist shady situa- 

 tions. It is a very variable plant in its extreme forms. The 

 fronds are rather flaccid, dark green, bi- or tri-pinnate, on long- 

 slender stipes, and usually somewhat deltoid in outline. Pin- 

 nules lobed to the rachis, furnished with awned teeth. A native 

 of Europe, Asia, North America, and North and South Africa. 



N. cemulum has a more triangular and divided concave 

 frond, smelling strongly of hay. 



3. N. Thelypteris. Marsh Fern. This is a delicate species 

 with creeping rootstocks, lanceolate pinnate fronds about a foot 

 or 18 inches, or even more high; pinnae deeply pinnatifid ; 

 pinnules entire. Stipes equalling or exceeding the leafy part 

 of the frond, very slender and nearly or quite naked. It grows 

 in marshy and boggy places, and the fronds are only of short 

 duration. Widely distributed. 



4. N. Oreopteris, syn. N. montanum. Sweet Mountain 

 Fern. A handsome mountain species with tufted lanceolate 

 pinnate fronds, pinna3 pinnatifid, glandular beneath, the lower 

 more distant and gradually smaller ; pinnules entire. Stipes 

 short, scaly. A native of Europe and Western Asia. 



There are several handsome Japanese species of this genus 

 belonging to the section Lastrea, as N. atratum, N. opacum, 

 and N. erythrosbrum. 



11. POLYP5DIUM. 



This genus is distinguished amongst hardy Ferns by its 

 globose sori, destitute of an indusium or involucre. Ehizome 

 creeping or tufted ; fronds simple, pinnatifid, or pinnate. Nearly 

 400 species of widely different habit are collected under this name, 



