524 Key to the System of 



2182. Somewhat beset with bristlets. 



Rather dwarf; root-stock creeping ; rootlets copious ; frond- 

 stalks scattered ; fronds almost deltoid in outline, firm ; 

 bristlets much dispersed, spreading, developed particu- 

 larly on the frond-stalk and rhachis, often black ; pinnas 

 nearly semi-lanceolar or the lowest more deltoid, all much 

 pointed ; segments- from elliptic- to linear-lanceolar, 

 sharply serrated or partly incised; fruit-cover almost 

 orbicular. A. hispidum. 



CUabrous or beset with soft hairlets ... ... 2183 



2183. Fronds of thick texture. 



Chiefly on trunks of fern-trees, usually rather tall, but occa- 

 sionally dwarfed ; root-stock creeping, much elongated ; 

 frond-stalks scattered ; fronds almost deltoid in outline, 

 sometimes only bi-pinnate, their stalks rough, scalelets 

 occurring mainly on the stalk and rhachis ; segments 

 comparatively large, mostly elliptic-lanceolar, bluntly 

 denticulated ; fruit-cover orbicular, rather large, early 

 seceding ; spores generally dark-colored. Figure 150. 



A. Capeuse. 



Fronds of thin texture 2184 



2184. Fruit-masses distant from the margin of the frond- 



segments. 



Tall ; root-stock creeping, rather abbreviated ; fronds long- 

 stalked, somewhat firm, dark -green on both sides, nearly 

 glabrous, rather shining, often almost deltoid in outline, 

 sometimes only bi-pinnate ; segments somewhat decurrent, 

 rather semi-lanceolar or slightly rhomboid, the upper con- 

 fluent, all irregularly and sharply denticulated or to 

 some extent incised ; divisions of venules generally few ; 

 fruit-cover quite small, orbicular-renate, frequently un- 

 developed. A. deconipositum. 



Fruit-masses near the margin of the frond-segments. 



Root-stock creeping, much elongated ; fronds large, long- 

 stalked, almost membranous, much beset with subtile 

 hairlets ; the lower pinnas the longest ; segments rather 

 acutely denticulated and partly incised ; divisions of 

 venules generally several ; fruit-cover quite small, 

 orbicular-renate. A. tenemm. 



