550 



THE BOOK OF CHOICE FERNS. 



upright, nearly smooth stalks 1ft. to 2ft. long, are furnished with leaflets 6in. 

 to Sin. long, cut two-thirds of the way down to the rachis (stalk of the leafy 

 portion) into close, sharply-pointed, nearly sickle-shaped lobes of a somewhat 

 leathery texture and bright green colour. The sori (spore masses) are disposed 

 near the midrib. — Hooker^ Synopsis Filiciim, p. 291. 



N. (Lastrea) Napoleon is— Las'-tre-a ; Nap-o-le-o'-nis (Napoleon's), Bory. 



This singular and thoroughly distinct, gTeenhouse species, limited to the 

 Island of St. Helena, is of medium size. Its shortly-triangular fronds are 

 1ft. to l^ft. long and Sin. to 12in. broad, and are borne on stalks 6in. to 

 12in. long, densely scaly at the base and naked upwards. The lowest leaflets 

 are much the largest. The pinnules (leafits) of the under- side, which are 

 the longest, are narrowly spear-shaped, closely set, and cut down nearly to 

 the rachis (stalk) into slightly-toothed, broad, blunt lobes of a somewhat 

 leathery texture. The sori (spore masses), disposed close to the midrib, are 

 covered with a smooth, naked involucre. — Eoolcei^, Species Filicum, iv., 

 p. 123, t. 255. 



N. (Eunephrodium) nevadense — Eu-neph-ro'-di-um ; nev-a-den'-se 

 (from Nevada), Eaton. 

 This very interesting, greenhouse species, which in North America is 

 known by the popular name of " Sierra Shield Fern," is, according to Eaton, 

 found in moist meadows and along creeks in the Sierra Nevada, North 

 California, especially in a meadow containing also the Swamp-loving Darling- 

 tonia, near Quincy, Plumas County, and in Berry Creek Canon, Butte County. 

 Its spear-shaped fronds, produced from a creeping rhizome (prostrate stem), 

 are IJft. to 3ft. long, including their short stalks, the lower part of which, 

 and the rhizome or rootstock, bear a 'few chaffy scales. These fronds are of 

 a thin, papery texture and pale green colour. The sori (spore masses), 

 situated close to the margin of the leaflets, are covered with a minute, kidney- 

 shaped indusium, furnished with a few dark-coloured, marginal glands, and 

 bearing several long, straight, jointed hairs on the upper surface. An 

 important feature to be observed in the fertile fronds, and which has not been 

 noticed in any other Fern, is that the divisions of the leaflets are closed or 

 folded together in the early part of the day, and only open in the afternoon. 



