GLOSSARY OF BOTANICAL TERMS. 229 



PERFECT, having stamens and pistils in the same flower, and in a 



perfect state for performing their functions. 

 PERFOLTATE, when the stem is surrounded by the base of the leaf, 



so that the former appears to pass through it. 

 PERI, a prefix to many words signifying around. 

 PERIANTH, when the calyx and corolla are not distinguishable, or 



either is absent. 



PERICARP, the covering of the seeds in the form of a seed-vessel. 

 PERIGONE, the covering of the seeds in the carices. 

 PERIGYNOUS, when the corolla and stamens are inserted in the 



calyx. 



PERISPERM. See ALBUMEN. 

 PERSISTENT, remaining, not falling off. 

 PERSONATE, a corolla in the form of an ancient mask, having two 



lips, with a palate closing the entrance into the tube. 

 PETALS, the divisions of the corolla. 

 PETIOLE, the stalk or support of a leaf. 

 PHANEROGAMOUS, PHANEROGAMIA, visibly furnished with stamens 



and pistils. 



PHYLLODIUM, a dilated petiole in the form of a leaf. 

 PHYLLOTAXY, the laws which govern the arrangement of leaves on 



the stem. 



PHYSIOLOGY (vegetable), the study of the vital functions of plants. 

 PILOSE, covered with long scattered hairs. 

 PINNAE, the leaflets of a pinnate leaf. 

 PINNATE, a compound leaf, having leaflets arranged on each side 



of a common petiole. 

 PINNATIFID, a simple leaf deeply cut into segments from the 



margin nearly to the midrib. 

 PINNULE, the leaflets of a bipinnate leaf. 

 PISTIL, the ovary, style, and stigma, occupying the centre of the 



flower. 

 PITH or MEDULLA, the soft cellular tissue occupying the centre 



of the stem in Exogens. 



PLACENTA, the part of the ovary to which the ovules are attached. 

 PLACENTATION, the arrangement of the placenta ; axillary, when 



the carpellary leaves meet in the centre or axis; parietal, 



when the carpellary leaves are joined by the edges or curve 



inwards but do not meet in the centre ; free central, when 



the placenta rises in the centre as a column to which the 



seeds are attached. 

 PLICATE, folded or plated. 

 PLUMOSE, resembling a feather. 

 PLUMULE, the central bud lying between the cotyledons in the 



embryo. 



POD, a one-celled, two-valved seed-vessel. 

 PODOSPERM, the small cord or stalk of the ovule by which it is 



attached to the placenta. 

 POLLEN, the small granules contained in the anther cells : pollen 



