CHAPTER XX. 



ADIANTUM, Linnaeus, 



( Ad-i-an'-tum.) 



Maidenhair. 



HE name Adiantum is derived from adia?itos, dry, and was given 

 no doubt in allusion to the singular property possessed by 

 most species belonging to this extensive genus, whose fronds 

 have the power of repelling water developed to such an extent 

 that, even after having been wholly submerged, they are, when 

 taken out of the water, found to be as dry as before. In Hooker and Baker's 

 " Synopsis Filicum," Adiantum forms Genus 21 : it is there said to have its 

 head-quarters in Tropical America, although a good many species are natives 

 of more temperate climates. Most of the known species are recognisable from 

 all other Ferns but the typical Lindsayas by the texture, as also by the 

 one-sidedness, of their segments (subdivisions), and by the absence of an 

 apparent and distinct midrib in the segments. The stipes and rachis (stalks) 

 of most Adiantums are black in colour, and have a glossy or polished appear- 

 ance. Usually the pinnee (leaflets) are either truncate (terminating abruptly), 

 as though they had been shortened by the removal of their extremity, or 

 wedge-shaped at the base, or dimidiate (fully developed on one side of the 

 midrib and scarcely at all on the other), and soriferous (spore-bearing) only 

 on the upper margin. The fronds are either simple (undivided), pinnate 

 (once divided to the midrib), pedate (shaped like a bird's foot), bipinnate 

 (twice divided to the midrib), reniform (kidney-shaped), or decompound 



