THE ANDROECIUM 



99 



in itself, seem to support the view that the fascicle is a unit organ, other 

 anatomical evidence shows the evolutionary development of tlie fascicle. 

 In the Paeoniaceae (Fig. 46), Dilleniaceae, Monimiaceae, and other 

 families, some stamens — especially those on the outside of the fascicles 

 — have simple, independent traces, and other stamens have traces 



Fig. 45. Stamen fascicles of Umbellularla showing lateral members transformed into 

 nectaries and stages in the loss of the nectaries, vascular supply to nectaries inde- 

 pendent and like that of the fertile stamen in type and origin, msp., micro- 

 sporangium; fi., filament; st.n., staminal nectary. ( After Kasapligil. ) 



loosely coherent with the "trunk," or connate with it for only a short 

 distance. (The anatomy of the vascular supply of fasciculate stamens, 

 especially the histological structure of the trunk vascular supply, is 

 little known.) 



The Whorled Androecium. Whorled arrangement in the androecium 

 represents a modification of spiral arrangement, as does the similar 

 condition in leaves. Where the stamens are in one whorl, the androecium 

 is haplostemonous; in two whorls, the members of the outer whorl al- 



