648 BOTANY or CROP PLANTS 



Phloem. — That portion of a vascular bundle which is largely concerned in 

 the transport of elaborated food material. 



Phyllotaxy. — The arrangement of leaves upon a stem. 



Pileole. — Coleoptile (which see). 



Pinnate (leaf). — ^Leaflets arranged along the sides of an axis. 



Pinnatifid. — Pinnately cleft to the middle of the blade, or further. 



Pistillate. — Bearing pistils only. 



Placenta. — The membrane or surface bearing ovules. 



Plicate. — Plaited. 



Plumose. — Plume- or feather-like. 



Plumule. — The first bud in the young plant. 



Polyadelphous (stamens). — Separate, or in more than two groups. 



Polygamo-dicecious. — Bearing both perfect and imperfect flowers on the 

 same plant, with a tendency to become dioecious. 



Polygamous. — Both perfect and imperfect flowers present on the same 

 plant. 



Pome. — A fruit in which the receptacle of the flower enlarges, becomes 

 fleshy and surrounds the carpels, as in apple, pear, and quince. 



Prehensile. — Adapted for holding. 



Prolandry. — In which the anthers of a flower shed their pollen before the 

 stigmas are receptive. 



Protogyny. — In which the stigmas of a flower are receptive before its anthers 

 shed their pollen. 



Pubescence. — Fine, soft hairs. 



Pubescent. — Covered with fine, soft hairs. 



Raceme. — ^Indeterminate type of inflorescence, in which the pedicels are 

 simple and one-flowered. 



Racemose. — Raceme-like. 



Rachilla. — The axis of a spikelet. 



Rachis. — The axis of a spike. 



Radical. — Seeming to come from the root. Leaves arising from the base 

 of stem, close to the ground line, are said to be radical, as contrasted with 

 those on the stem (cauline). 



Ray. — The branch of an umbel; marginal, ligulate flowers of a composite 

 head. 



Receptacle. — The end of the axis to which the floral organs are attached; 

 torus. 



Rejlexed. — Turned back. 



Regular (flower). — The parts of each whorl similar. 



Uewj/orjw.— Kidney-shaped. 



Reticulate. — Netted. 



Retrorse. — Turned back or downward. 



