ADIANTUM. 61 



creeping stem, which is clothed with small black scales, and 

 bears delicate, graceful, somewhat drooping fronds, of six 

 inches to a foot high. These fronds are usually of an 

 irregularly ovate form, sometimes elongate, occasionally 

 approaching to linear. Finely developed fronds are about 

 thrice pinnate; but the less vigorous fronds are usually 

 only twice pinnate, with alternate pinnae and pinnules ; and 

 sometimes fronds are found which are only once pinnate. 

 The ultimate pinnules, or leaflets, are very irregular in shape, 

 but for the most part have a wedge-shaped or tapering 

 base, and a more or less rounded and oblique apex, and 

 they have generally some variation of a fan-shaped or rhom- 

 boidal outline. The margin is more or less deeply lobed, 

 the apices of the lobes in the fertile pinnules being reflexed 

 and changed into membranous indusia, whilst the lobes of 

 the barren fronds are serrated ; their texture is thin and 

 membranaceous, their surface smooth, their colour a 

 cheerful green. The stipes, which is about half as long as 

 the frond, and furnished with a few small scales at the base, 

 is black and shining, as also are the raches, the ultimate 

 ramifications of which are small and hair-like. 



The veins throughout the pinnules are forked on a di- 

 chotomous or two-branched plan, from the base upwards, 



