Classification of Plants 



327 



the Cactus plant, the stem may be reduced to a roundish or 

 club-shaped body, surrounded with cushions of leaf bases. 

 Frequently a pair of stout thorns represent stipules of abortive 

 leaves. An axillary thorn (reduced inflorescence) occur in 

 some species. (Cactus has clustered thorns.) What at first 



FIG. 306. Euphorbia Lathyris, L. I. Fart of a plant. II. Inflorescence. 

 III. Male flower (magnified). (From Thom6 and Bennett's "Structural and 

 Physiological Botany".) 



seems to be a single flower is an inflorescence consisting of a 

 group of staminate flowers and a single pistillate flower. The 

 pistillate flower is raised on a stalk, and is reduced to an ovary. 

 Each staminate flower is also raised on a little stalk or pedicel, 

 and consists of a single stamen. The central stamens ripen 

 first. The whole inflorescence is surrounded by a cup-shaped 



