490 



THE BOOK OF CHOICE FERNS. 



divided to the midrib, are seldom more than Bin. long. The pinna; 

 (leaflets), with which they are furnished on each side, are about as broad 

 as long, and are cut into three secondary pinnules (leafits), the low 

 lateral ones of which are wedge-shaped ; all are cut into numerous long- 

 pointed teeth, the central ones being the largest. The ultimate segments in 

 some fronds are linear (thread-like).— Lowe, Our Native Ferns, ii., p. 181, 

 fig. 526. 



A. A.-n. leptorache— lep-tor-ach'-e (having slender rachises or stalks), 

 Moore. 



This curious form, originally found in Glen Urquhart, in the Highlands, 

 is remarkable for the length and the peculiarly slender nature of its stalks 

 compared with the small dimensions of the leafy portions of the fronds ; for 

 while their stalks are quite 7in. long, the leafy parts of the fronds are 

 barely Sin. long, ovate (egg-shaped), tripinnate (three times divided to the 

 rachis), and shortly acuminate (terminating in a tapering point). The 

 pinnae (leaflets) are alternate (not opposite) and divided into small, 

 wedge-shaped pinnules (leafits), which are themselves pinnatifid (divided 

 half-way to the stalk) in the upper half. Each lobe is tipped with two 

 small, very sharp teeth. This variety produces spores in great abundance. 

 — Lowe, Our Native Ferns, ii., p. 179. 



A. A.-n. microdon— mi'-crod-on (furnished with small teeth), Moore. 



This very distinct variety, of medium size, originally found in a wild 

 state in Guernsey and near Barnstaple, has fronds 6in. to 8in. long, including 

 the stipes (stalks) ; they are broadest at the base, where they measure nearly 

 3in. across, and, compared with the fronds of either the original species or 

 its other known varieties, are very little divided. The pinnas (leaflets) are 

 distinctly pinnate (cut down to the stalk) at the base, and are only pinnatifid 

 (cut down partly to the stalk) above and in the upper part of the frond : 

 they terminate in a broad, irregular apex cut only half-way to the midrib. 

 These pinna3 have all the appearance of being entire (undivided), but their 

 margin is everywhere minutely and sharply toothed. The sori (spore 

 masses) in this curious form are placed near the costa (midrib) of the fertile 

 leaflets. — Lowe, Our Native Ferns, ii., p. 174, fig. 515. 



