INTRODUCTION 
This book) FT follows the pattern oi the earlier numbers 
of this series. 
A bulb is a storage organ whose function is to carry the 
plant over unfavourable climatic conditions from one grow- 
ing season to the next. It is a thickened, fleshy and often 
subterranean part of the plant with a bud for renewed 
growth, and bearing roots. A true bulb is composed of 
concentric layers of fleshy leaf bases (onion) or of scales, i.e. 
reduced leaves (some lilies), but in common usage bulbs 
refer to plants with a variety of storage organs of different 
morphological origin such as conns (gladiolus), tubers 
(dahlia), rhizomes (can n as), etc. In an uniformly favourable 
growing climate such as there is over much of Malaya 
certain introduced bulbous plants which normally base a 
resting period in their growth cycle do not receive the 
stimulus to rest, so that they grow themselves to exhaustion. 
Careful lifting, drying and storage is sometimes successful 
in maintaining planting stock. 
The commonest bulbous plant in Malayan gardens is the 
Canna. 
H. M. BURKILl, 
Director, Botanic Gardena, 
March 1958 Singapore. 
|c<? 
