370 



THE BOOK OF CHOICE FERNS. 



dimensions, usually produces several crowns or heads, and by the division 

 of these the plant can be increased. 



A. pterorachis— pter-or'-ach-is (having a winged stalk), Baker. 



A stove species, from Tarapota, East Peru, with fronds 3ft. long, 

 bipinnate (twice divided to the midrib), rendered conspicuous by the peculiar 

 grey colour of their smooth stalk and rachis (stalk of their leafy portion), 

 both of which are covered with spear-shaped scales of a dark brown colour, 

 with a distinct pale border. The upper pinnae (leaflets) are stalkless, but 

 the lower ones are distinctly stalked, spear-shaped, 5in. to 6in. long and 

 ljin. to 2in. broad, and furnished with numerous strap-shaped and closely- 

 set pinnules (leafits) of a thin, papery texture, smooth, and bright green on 

 both sides. The very small sori (spore masses) are set in either one or 

 two irregular rows midway between the edge and the midrib of the fertile 

 pinnules. — Hooker, Synopsis Filicum, p. 456. 



A. pubescens— pu-bes'-cens (downy), Baker. 



This stove species, native of Peru and New Granada, is of very decorative 

 habit. Its stem or trunk, of a slender and flexuose (undulating) nature and 

 conspicuously marked with oval scars, attains about 10ft. in height. The 

 ample fronds are oblong in form, 3ft. to 4ft. long, bipmnatifid (twice divided 

 half-way to the midrib), borne on robust, smooth, brown stipes (stalks) 

 about lft. long ; the rachis (stalk of the leafy portion), instead of being 

 scaly as in most species, is densely covered with fine, spreading, grey hairs. 

 The pinnse (leaflets) are shortly stalked, strap-shaped, 5in. to 6in. long and 

 lin. broad, cut down to a narrow wing into close, entire, blunt lobes of 

 a moderately firm texture, and finely downy all over both sides. The sori 

 (spore masses) are situated at the forking of the veins, near the midrib of 

 the fertile pinnules. — Hooker, Synopsis Filicurn, p. 32. 



A. pungens — pun'-gens (very sharp-pointed), Kaulfuss. 



A stove species, native of British Guiana. Its ample fronds are tripin- 

 natifid (three times divided half-way to the midrib), and furnished with 

 oblong-spear-shaped leaflets lft. to ljft. long, which are divided into stalkless, 

 spear-shaped, pointed pinnules (leafits) 3in. long and Jin. broad, cut down 



