GLOSSARY OF BOTANICAL TERMS 539 



Petal. — A division of the corolla. 

 Petiole. — The foot-stalk of a leaf. 

 Pinnate leaves are compound leaves, in which the leaflets are arranged 



on a common stalk, which answers to the mid-rib of a simple leaf. 

 Pistil. — The central, seed-bearing flower organ, including ovary, style, 



and stigma, the style not being an essential part. 

 Placenta. — That part of the ovary which bears ovules or seeds. 



Raceme. — Numerous flowers on separate pedicels, upon an elongated axis. 



Beneath each flower is, usually, a small bract. 

 Rachis. — The principal axis or stem in an elongated spike or cluster of 



flowers. 

 Receptacle. — The tip of the flower-stalk, upon which the floral parts are 



regularly arranged. 

 Rootstock. — A prostrate or underground stem, usually erect at apex, rooting 



at nodes. 



Samara. — A winged, indehiscent fruit, as of the maple. 



Scape. — A flower-stalk arising from the root, without true leaves. 



Sepal. — Division of the calyx. 



Serrate. — Like the edge of a saw. teeth pointing forward. 



Serrulate. — Finely toothed. 



Sessile. — Sitting. Of a leaf or flower destitute of stalk. 



Spadix. — A spike of flowers with a fleshy, long axis. 



Spathe. — A large leaf-like bract, enfolding a flower cluster or single flower. 



Spike. — Sessile, or nearly so, small flowers arranged upon an elongated 



axis. 

 Stamen. — The pollen-bearing organ of the flower, standing next outside 



the pistil, consisting of anther and filament, the latter not always 



present. 

 Standard. — The posterior, large petal of the flower of the pulse family, 



enfolding the others in bud. 

 Stem. — The leaf-bearing part of a plant ; erect, prostrate, or subterranean. 

 Stipules. — The appendages which sometimes grow on the opposite sides of 



a leaf, at the base of its petiole. Sometimes they sheathe the stem, 



as in buckwheat. Sometimes, as in clover-leaves, they extend along 



the leaf-stalk. Often they are like small leaves or bracts. 



Umbel. — The kind of inflorescence which includes several flowers spring- 

 ing from the same pomt. 

 Umbellet. — Smaller, secondary umbels. 



Wings. — The side-petals of the papilionaceous corollas. 



