568 



THE BOOK OF CHOICE FERNS. 



green in colour. The small and numerous sori (spore masses), often eight to 



twelve to a lobe, are covered with an involucre of a very fugacious nature. 



Hooker, Species Filicum, iv., p. 142, t. 269. 



This species, which is very variable in size and general appearance, 

 sometimes produces fronds more or less crested ; completely crested young 

 plants have even been observed, though never named or described by any 

 authority. 



N. (Lastrea) setosum— Las'-tre-a ; se-to'-sum (bristly), Baker. 



A delicate and distinct, stove species, native of Java, also known as 

 Aspidium setosum. Its fronds, Ift. to IJft. long and 6in. to 9in. broad, are 

 borne on tufted stalks 4in. to 6in. long, densely clothed with scales of a light 

 brown colour. The lowest leaflets are the largest, and the pinnules (leafits), 

 usually spear-shaped, are cut down to the midrib into long, narrow segments. 

 The fronds are of a soft, papery texture and naked on both surfaces. The 

 sori (spore masses) are disposed in a line close to the midrib. — Hooker, 

 Synopsis Filicum, p. 274. 



N. (Lastrea) Sieboldii— Las'-tre-a ; Sie-bold'-i-i (Siebold's), Hooker. 



This greenhouse or even hardy species, native of Japan and China, in 

 the neighbourhood of Hong-Kong, and also known in gardens as Pycnopteris 

 Sieholdii, is a thoroughly distinct Fern, possessing very little of the general 

 appearance of a Nephrodium. Its singular fronds, of two different kinds, are 

 produced from a decumbent rhizome (prostrate stem) of a very succulent 

 nature, and covered with large, brown, spear-shaped scales. Barren and 

 fertile fronds alike are simply pinnate (only once divided to the midrib), being 

 composed of an entire or slightly-toothed, broadly spear-shaped terminal 

 leaflet Sin. to 12in. long and IJin. to Sin. broad, and from two to four 

 similar ones on each side, the lowest shortly stalked. Both kinds of fronds 

 are of a coriaceous (leathery) texture, smooth, and glaucous (bluish). The 

 leaflets of the barren fronds, which are borne on roundish, light green stalks 

 seldom more than Sin. long, are somewhat undulated. In the fertile fronds, 

 which are borne on stalks frequently 1ft. long, they are more contracted and 

 entirely covered with large sori (spore masses), scattered irregularly. — Hooker, 

 Species Filicum, iv., p. S7 ; Filices Exoticce, t. 31. Nicholson, Dictionary 

 of Gardening, ii., p. 444. Loioe, Ferns British and Exotic, vi., tt. 34 and 35. 



