456 



THE BOOK OF CHOICE FERNS. 



Its fronds, which sometimes attain 3ft. in length and 1ft. in breadth, are 

 borne on stipes (stalks) 1ft. long, and clothed below with large, egg-shaped 

 scales, which, like those of the upright and somewhat woody rootstock, 

 are of a dark brown colour, marked by a peculiar darker colour still in 

 their central spot, and gradually wear off as the fronds get mature ; they 

 are simply pinnate (only once divided to the midrib), of a coriaceous 

 (leathery) texture, and everywhere bordered by a narrow, cartilaginous 

 (gristly) edge, which is extended into sharp teeth, especially towards the 

 ends of the pinnae (leaflets) ■ both surfaces are smooth and shiny. 

 These pinnae, short-stalked at the base and stalkless towards the summit of 

 the frond, are narrow-spear-shaped, 4in. to 6in. long and about lin. broad, 

 and disposed from six to twelve on each side of the midrib, besides a 

 terminal one, which is longer and a little larger than the others. The sori 

 (spore masses) are usually disposed in a row on each side of the midrib and 

 at a little distance from it ; but there is frequently outside of each of these 

 rows a second and less complete one of more or less scattered sori : these sori 

 are covered by an orbicular indusium, which is quite peltate (attached to the 

 frond by its centre). In its natural habitats this Fern is of very variable 

 dimensions ; thus, while in Venezuela it attains the height of 3ft., it is 

 commonly of lower stature in Mexico, and the Texas plant is seldom above 

 lft. high, stalk included. — Hooker, Species Filicum, iv., p. 38. Eaton, Ferns 

 of North America, ii., t. 75. 



A. (Polystichum) lachenense — Pol-ys'-tich-um ; lach-en-en'-se (from 

 Lachen), Hooker. 



A greenhouse species, of small dimensions, native of the Sikkim and 

 Himalayan Mountains, where it is found wild at elevations varying between 

 13,000ft. and 16,000ft. Its pretty little fronds, of a leathery texture, 4in. to 

 8in. long and about fin. broad, are borne on stout, black stems 2in. to 4in. 

 long, clothed below with large, spear-shaped scales ; these fronds are pinnate 

 (once only divided to the midrib), and the pinnae (leaflets), £in. to Jin. long, 

 have their sides equal, their point blimtish, and their edge serrated (toothed 

 like a saw). The sori (spore masses) are produced in great abundance, often 

 covering the whole under-surface of the pinnae. — Hooker, Species Filicum, iv., 

 p. 8, t. 212. 



