GLOSSARY 375 



Persistent, remaining on after flowering. 



Petal, one of the non-esseutial organs of a flower, usually delicate and 



coloured. 

 Petaloid, like petals, p. 43. 

 Petiolar glands, glands on the petiole, p. 211. 

 Petiole, the leaf-stalk, p. 219. 

 Phyllotaxy, leaf-arrangement on the shoot, p. 56. 

 Pilose, softly hairy, p. 317. 



Pinnate, with leaflets right and left on a main stalk, p. 264. 

 Pinnatifid, cut in a pinnate fashion. 

 Pistil, the totality of carpels, p. 43. 



Pistillate, flowers or inflorescences hearing carpels only ; see Female. 

 Pith, the central tissue of a stem, p. 239. 

 Placenta, the tissue from which the ovules arise. 

 Placental scale, the scale of a pine-cone, &c., which bears the ovules, 



p. 175. 

 Placentation, the arrangement, &c., of the ijlacentse. 

 Plumule, the primary bud of the embryo or seedling, p. 200. 

 Pod, see Legume. 

 Polished, shining, glossy, p. 268. 



Pollen, the powdery mass of spores which is contained in the anthers. 

 Pollen-grains, the microspores or units of which the pollen consists. 



Pollen-sac, the cavity in the anther in which the pollen developes. 



Pollen-tuhe, the germ-tube emitted when the pollen-grain germinates. 



Pollination, transmission of i)ollen-graiu to stigma. 



Pollinium, a mass of pollen-grains which retain their coherence. 



Polyadelphous, in several clusters or bundles. 



Polyandrous, with numerous stamens. 



Polycarpellary, of many carpels. 



Polychasium, like a dichasium but three or more branches arise each 

 time, p. 35. 



Polygamous, with (? , ? , and $ flowers on the same plant, p. 155. 



Polymorphic, of several or many shapes. 



Polymorphy, showing variations in shape. 



Polypetalous, with several separate petals. 



Polypetaly, with free petals, p. 63. 



Polysepalous, of several separate sepals. 



Polysepaly, with free sepals, p. 63. 



Pome, a fruit of the apple tyi^e, p. 322. 



Porogamic, where the pollen-tube enters the micropyle in fertilisation, 

 p. 171. 



Primary axis, the main shoot or stalk of the inflorescence, &c., p. 17. 



Proliferous, growing forward after a pause, p. 182. 



Prostrate, flung on the ground, p. 205. 



