THE HERBACEOUS DICOTYLEDONS 



399 



into typical wood, precisely as has been shown above to occur 

 in the vine. A careless study of the facts and, above all, a neglect 

 to examine the conditions present in the region of the node, might 

 lead to the conclusion that the leaf trace in the more primitive 

 and lower woody portion of the stem in Urtica is flanked but not 

 confronted by storage parenchyma. 



Although the Urticaceae have been chosen to illustrate the 

 herbaceous condition in a comparatively low order of dicotyledons, 



a o 



FIG. 276. a, part of the thick stem of the nettle immediately below the node; 

 b, section of the same some distance below the node. Explanation in the text. 



the Ranunculaceae, as represented by the woody and herbaceous 

 species of Clematis or the more slender and thicker region of the 

 same woody species, yield like results. A group in an approxi- 

 mately intermediate position systematically is the Rosaceae. 

 Herbaceous representatives when compared with woody forms 

 of allied organization yield similar conclusions. For example, 

 in Rubus we find well-marked compound rays, which both flank 

 and subtend the foliar traces. In many herbaceous types of the 

 genus Potent ilia broad rays like those of the oak are found in the 



