V EG ETA TIVE REP ROD UCTION. 



257 



Fig. 280. — Inflorescence of the dogwood (Cornus florida), showing four white bracts 

 below it, giving the whole cluster the aspect of a single flower. Two thirds natural 

 size. — After Baillon. 



Fio. 281. — Inflorescence of yarrow {Achillea millefolium). A, seen from above; B, 

 in longitudinal section, i, bracts, forming the involucre ; d, bracts in whose axils the 

 flowers stand; ra, the ray flowers; w, the disk flowers; c, corolla;/, ovulary ; n, 

 stigmas ; r, the common torus. A magnified about 8 diam. ; />', about 15 diam — Alter 

 Prantl. 



