154 NAMES OF PLANTS. 



Bistor'ta, Mattliioliis. L., twice -twisted (bis-forta) ; al. 

 luding to its roots. 



Fagop'yrum, Dodonreus. It was also called Fagotriticum 

 (L. Fagtis, a beech, and Tritkumy wheat). Fago- 

 pyrum is the same name in G., phegos, a beech, and 

 pyros, wheat ; on account of the resemblance of the 

 three-cornered seeds to beech-mast. See Fagus. 



Convolv'ulus. See the genus earlier; so called from its 

 twining habit. 



Hydropi'per. See under Elatine. 



PersicaWia, Pliny. From L. persicus, a i^each tree ; on 

 account of the resemblance of the leaves. 

 Polypod'ium, or po'dium, Theophrastus. From G. _2^oZ2/, 

 many, and podion, a little foot; on account of the 

 divisions of the rhizome. 



Dryop'teris, Dioscorides. G., dryo, oak, and pteris, fern; 

 Oak Fern. Five of our British ferns have been 

 called Dryopteris by different authorities at different 

 times. 



Phegop^teris, Linneus. From G. phego, a beech tree (see 

 Fagus), and pteris, a fern. Beech Fern. 

 Polypo'gon. From G. poly, much, and p)ogon, beard ; from 



the bearded appearance of the panicle. 

 Polys'tichum. From G. poly, many, and sticlws, order; 

 " applied to the shield ferns in allusion to the nume- 

 rous regular lines of sori, which are seen distributed 

 over the fronds." — Moore. 

 Pop'uLUS, Pliny. L. name for the Poplar ; the derivation 

 is doubtful. It has been suggested that it is an 

 altered form of palpaliis, from G. 2^(f^llomai, to quiver, 

 or shake ; which the leaves of the Aspen and other 

 Poplars are remarkable for doing. 

 Potamoge'ton, Dioscorides. G., potamo, river, and geiton, 

 a neighbour, They are water plants. 



