160 GLOSSARY 



Petals. The inner floral leaves, forming the corolla. 



Petiole. The leaf-stalk. 



Phanerogams. Flowering- or seed-plants. 



Phylloid shoots. The foliage of pines; morphologically con- 

 sidered as modified branches of the stem, rather than 

 leaves, by some. 



Phylum. The same as division. 



Pinnate. Distributed along an axis, like the plume of a feather 

 on the quill (leaflets of an elder leaf; the lobes or veins of 

 an oak leaf, etc.). When unqualified it means pinnately 

 compound, if applied to leaves. When the leaflets of a 

 pinnate leaf are again pinnate, the leaf isi bipinnate or 

 twice pinnate. Unequally pinnate or bipinnate leaves vary 

 greatly in their compoundness, often in the same leaf 

 (honey locust). 



Pistil. The part of a flower that produces ovules and seeds. 



Pistillate. Flowers that have pistils but no stamens. 



Pith. The central part of a stem, surrounded by the woody 

 cylinder: usually continuous and of uniform texture, but 

 sometimes with firmer plates or diaphragms at the nodes 

 (grape) or at intervals between them (sour gum, sweet 

 bay) ; in some genera disappearing or excavated (honey- 

 suckle), or chambered between persistent thin plate? 

 (golden bell, walnut). 



Placenta. The part of the pistil to which seeds are attached. 



Polygamous. With both perfect and imperfect flowers (maple). 



Polypetalous. With petals not grown together, as in a rose. 



Pome. An apple-fruit, the fleshy pulp crowned by the calyx or 

 other vestiges of the flower, and separated from the seeds 

 by a papery (apple) or bony (red haw) core. 



Prickle. A pungent outgrowth of the cortex or bank of a stem, 

 or of the surface of a leaf: contrasted with spines, which 

 are modified forms of leaf or stem. 



Prostrate. Low and spreading, as applied to shrubs: trailing. 



Puberulent. Minutely pubescent. 



Pubescent. With hairs. 



Pungent. With sharp hard point. 



