io6 THE BOOK OF RARER VEGETABLES 
a height of from 
6 to 9 feet. 
The growth is 
not unlike the 
Black Bryony 
found so plenti- 
fully in hedge- 
rows in some 
parts of the 
country, as the 
twining stems 
and shining 
heart - shaped 
leaves much re- 
semble Byrony. 
The second 
named variety is 
more like our 
own Potatoes, 
smooth and 
regular in some 
instances, in 
others very 
irregular, and 
the roots do not 
require such a 
deep soil as they 
grow much 
nearer the sur- 
f a c e. This 
variety has been 
cultivated in 
many countries 
and was intro- 
duced into France in 1854, and this, or a plant but differ- 
ing little in shape and growth, is largely grown in South 
CHINESE YAM 
{One-sixth tiatural size) 
