ETTMOLOGT. 299 



Phleloodium, phlehes, veins, odous, a tooth ; tHe joining of the 



veins in the areoles" being like teeth. 

 Phymatodea, plvymata, tubercles ; the impressed sori having 



the appearance of tubercles on the upper side of the 



frond. 

 Pilularia, jjiZmZct, a pill; the form of the spore-cases. 

 Platycerium, platys, broad, heras, horn ; the fronds divided in 



broad segments like stags' horns. (The stags' -horn 



fern.) 

 Platyloma, platys, broad, loma, border ; having broad sori close 



to the margin. 

 Pleoonemia, 'pleos, full, Jcnemia, rays ; full of rays ; the vena- 

 tion. 

 Pleopeltis, pleos full, peUis, shield ; the sori being furnished with 



numerous round scales. 

 Pleuridium, pleura, side (ribs) ; the primary veins being costse- 



form, like ribs. 

 PoecUopteris, pcelcilos, spotted, pteris ; the appearance of the 



venation. 

 Polybotrya, polys, many, hotrys, bunch ; the fructification being 



in bunch-like racemes. 

 Polypodium, polys, many, pons, foot ; polypus ; the rhizome, 



when destitute of the fronds, having the appearance of 



some kind of sea-polypus. 

 Polystichum, polys, many, stichos, order ; not specially 



applicable to the genus Polystichum, as now defined. 

 Psilotum, psilos, naked ; destitute of leaves. 

 Psomiocarpa, psomion, a small pellet, ha/rpa, fruit ; the 



sporangia being in small round patches, in spikes. 

 Pteris, pteryx, wing; the scientific name given to the plant 



known by the names of Brake, Bracken, and Fern; 



on account of the supposed hk'eness of the branching 



of its fronds to wings. This, being the commonest 



ot" all Perns, has become the type of the whole race; 



hence Pteris means Fern, all generic names of ferns 



ending in pteris; such as Ceratopteris means horned 



Fern, Diotyoptens netted Fern ; also, if at the beginning 



of a word, as Pteridography, a book oi' writing on Perns ; 



Pieridologist, a studier and writer on Perns ; Pteridopliilist, 



a lover of Perns. 



Ehipidopteris, rhipie, fan ; shape of the fronds like a fan. 



