RANALES 425 



The corolla in the Ranales may consist of one, two, three, or even 

 more series; these series are subwhorled and more or less distinct in 

 form and color. Reduction in petal whorls is apparent in the Nymphaea- 

 ceae-Cabombaceae and Magnoliaceae-Annonaceae. Stages in the reduc- 

 tion in petal number are present in the Winteraceae, Magnoliaceae, and 

 Annonaceae. In Drimijs, the petals are reduced from several or many to 

 two. 



The origin of the corolla from stamens is apparent in many families 

 by the presence of transitional organs and by anatomical structure. 

 (The number of traces to petals is usually the same as that to stamens 

 and unlike that to sepals. ) The outer tepals of the Nymphaeaceae are 

 perhaps, morphologically, bracts and the inner are stamens, with many 

 transitional forms. (The somewhat similar petals of Faeonia, in the 

 Dilleniales, are all bracteoid; there are no staminodes.) The con- 

 spicuous, petaloid staminodes of Eiipomatia form a pseudocorolla, a 

 corolla above the stamens (frontispiece). (Hinmnfandra has stami- 

 ' nodes both above and below the stamens. ) Perhaps the upper position 

 of petaloid organs in these two genera represents an ancient type of 

 corolla, adapted to pollination by beetles only. 



Stamens. The androecium of the Ranales shows in the laminar stamens 

 — especially in Degeneria (Fig. 145), Himantandra, and the Nymphaea- 

 ceae ( Fig. 54 ) — convincing evidence of the leaf nature of this sporophyll 

 — form, origin by marginal and apical growth, vascular supply. All 

 transitional stages from the simple, sessile blade to distinct anther and 

 filament are present. The paired arrangement of the sporangia — two 

 on each side of the midvein — is already established in the most primi- 

 tive stamens, as is the position of the pairs — on the blade between the 

 midrib and margin, without direct relation to the major vascular supply. 

 The arrangement in two pairs — in strong contrast to the variety in 

 ovule number and arrangement — persists throughout higher angio- 

 sperms. Other highly important characters are the sunken position of 

 the sporangia and the absence of a sporangial wall. There are many 

 stages in the protiusion of the sporangia and their protection by anther- 

 sac walls built of laminar tissue. The value of the protruding connective 

 tip as a primitive character in angiosperms is shown by its prominence 

 and nearly constant presence in the ranalian families. 



Interpretation, with convincing evidence, that the nectary-bearing 

 stamens of the Lauraceae, Gomortegaceae, and some of the Monimia- 

 ceae represent modified stamen fascicles brings fasciculate stamens into 

 the picture of the relationship of the Ranales to the Dilleniales. Separa- 

 tion of these two orders has been based on few characters, among them 

 the presence of fasciculate stamens in the Dilleniales and their absence 

 in the Ranales. The fascicles of the two orders differ, in that those of 



