GLOSSARY 347 



O 



Orchis — A <^ciuis of the (Jixliid lainily j^rowiiij^ in tlic soil. 

 Osmosis — Tlic passaj^c ot liiiids tliroiij^li a iiK-mlnaiu-. 

 Oviirv — The ovule case, that part of tlie carpel that iuars 



ovules. 

 Ovule — The structure wliicli after tertilisation tornis the 



seed. 

 Ovum — The egjf ceil ot tile ovule. 

 Oxalis — Tlie generic name of tlie wood sorrei. 

 Oxyilcii — A »jas, one of tiie constituents of tlie atniospiiere. 



Palisaih'-tissuc — A tissue of oblong cells placed side by side 



at rit^ht angles to the flat surface of the leaf. 

 Papilionaceous — KutterHv sliaped. 

 Pappus — A light hairv development from tiie caivx of some 



plants. 

 Parasitic — Tiie liabit of growing upon and fleriving nourisii- 



nient from another plant. 

 Pcllucul — Siiining and transparent. 

 Perennial — Plants tiiat live for an indelmite period. 

 Perianth — A term used wiien tiiere is no distinction between 



caivx and corolla. 

 Pericarp — The ripened walls of the ovarv constituting tiie 



structure of tiie fruit. 

 Persistent — Applied to tiie parts of tiie Mower tiiat remain 



on for some time. 

 Petunia — A genus of Brazilian Soianaceie. 

 Philoiicndron — A genus of aroids usually climbers. 

 Phlcum — A grass. 



Phloem — The inner baric, containing sieve-tubes. 

 Phospliate — A salt formed liy tiie union of piiosphoric acid 



witii some base. 

 Phvllotaxis — Tlie law of leaf arrangement. 

 Phvsalis — The generic name of the winter clierrv. 



