112 BRITISH PLANTS 
with membranous scales ; in bulbs the food is in the leaves, 
which are thick and fleshy, the stem being reduced to a 
flattened disc, bearing roots (see p. 156). 
Classification of Plants according to their Frequency 
of Seeding. 
This is a more scientific method than by longevity, 
which is governed by the seasons. We have already 
pointed out that there is no strict line of division between 
Fic. 31.—SwEDE, SHOWING TUBER- Fie. 32. — KoHLRABI, SHOWING 
ous Hypocotyn. (REDUCED.) TuBEROUS STEM BEARING LEAF- 
dé opllan”? Scars (a). (REDUCED.) 
annuals and biennials, or between biennials and peren- 
nials, and the estimation of age by the seasons fails alto- 
gether in the case of plants which live in those parts of 
the Tropics where there is no climatic interruption in the 
development of the vegetation. 
According to the frequency of seeding, plants are 
divisible into two groups : 
1. Monocarpice Plants (Gr. monos, once ; carpos, fruit), 
which produce seed once and then die, and— 
2. Polycarpie Plants (Gr. poly-, many), which fruit more 
than once in their lifetime. 
