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. 
