44 



ARISTOLOCHIACEAE. 



ARISTOLOCHIA. Dutchman's Pipe. 

 (Family Aristolochiaceae). 



Soft-wooded twiners: deciduous. 

 Stems terete, green, swollen at 

 the nodes: wood with large dif- 

 fused ducts and broad medullary 

 rays: pith large, rounded, con- 

 tinuous, pale. Buds small, ses- 

 sile, rounded, superposed on a 

 silky area in arch of the leaf-scar, 

 with 1 silky scale, the end-bud 

 lacking. Leaf-scars alternate, U- 

 shaped, somewhat raised: bundle- 

 traces 3: stipule-scars lacking. 



The Dutchman's pipe is one of 

 many plants in which axillary 

 buds are not to be seen until after 

 the leaves have fallen. This is 

 not because they are absent or 

 sunken in or covered by the bark, 

 but because, like those of Plata- 

 nus, Cladrastis and other genera, 

 they are enclosed in a cup-like 



enlargement of the petiole base. When the leaf is removed, 

 or after it has fallen, this is quite evident, though the Aristo- 

 lochia buds are small and less easily seen than those of Pla- 

 tanus or Cladrastis. Like those of the latter, they are not 

 solitary in the axil, but in a series of several superposed one 

 above the other. In a paper on such serial buds published 

 in 1884, Velenovsky showed that this multiplicity of buds 

 produced above ground is not shared by subterranean buds, 

 which are solitary, in Aristolochia. 



Stem glabrous. (1). A. macrophylla. 



Stem puberulent. A. tomentosa. 



