280 GLOSSAEY AND INDEX. 



oogonium (pi. oogonia), the female reproductive organ of certain cryp- 

 togams. In it is produced an oosphere (or in some cases more than 

 one), which after fertilization becomes an oospore, 105. 



obphyte, 98, 129, 146, 151. 



oosphere, a cell which, as a result of fertilization, forms a cell-memhrane 

 and subsequently develops into a new plant, 84, 96, 126, 129, 134, 151. 



oospore, the fertilized oosphere, 96, 105, 108, 126. 



operculum, the lid of the spore-case of mosses, 123. 



order, 156. 



orthotropous, 16. 



ostiole, a minute opening through which spores or spermatia are dis- 

 charged, 114. 



ovary, the part of the pistil that contains the ovules, 74. 



ovule, the body that after fertilization becomes the seed, 75, 84. 



palate, a fold of the lower lip of a bilabiate corolla, partially or wholly 

 closing the throat, 244. 



palet, the inner bractlet of the flower of grasses ; one of the bractlets or 

 scales subtending the individual flowers of a head, 159. 



palisade-cells, the elongated chlorophyll-bearing cells arranged like pali- 

 sades beneath the upper epidermis of most leaves, 60. 



palmate, having a hand-like or fan-like arrangement, or divided like a 

 bird's foot, 58. 



pappus, the modified calyx-limb of a composite flower, 257. 



paraphyses (sing, paraphysis), filamentous outgrowths occurring with 

 antheridia and other reproductive bodies, 114, 125. 



parasite, a plant or animal that fastens upon and draws its nourishment 

 from another living organism instead of producing its own food, 36, 

 117, 118. 



parenchyma, tissue composed of cells that are but little longer than broad 

 or often isodiametric. In shape the cells may be oblong (palisade 

 tissue), rounded (loose tissue), polyhedral (pith), muriform (medul- 

 lary rays), stellate (Juncus stems), etc. Usually parenchyma cells 

 contain protoplasm and are functionally active. There are various 

 transitions into prosenchyma, which see. 



parietal, pertaining to the wall, as parietal placentae, which are borne on 

 the wall, or form part of the wall, of the ovary. 



parted, divided almost to the base, 58. 



pedicel, the stalk of an individual flower of an inflorescence. 



peloria, a condition in which flowers normally irregular become regular 

 and symmetrical, 247. 



pepo, the gourd-fruit of the Cucurbitaceae, 94. 



