Tlie GroivtJi- Forms of Natal Plants. 
609 
die down at the approach of winter. Small cushion forms and plants with 
long diageotropic shoots also come into this class. 
Hemicryptophytes have their dormant shoot apices just below the sur- 
face of the soil during winter. The aerial parts die down. It is often very 
difficult to separate this class from the classes Chamaephytes and Geophytes. 
They naturally grade into one another. 
GrEOPHYTES are plants with underground bulbs, rhizomes, and tubers of 
various kinds. The food material thus stored enables the renewal buds to 
be more deeply situated in the soil. 
Helophytes are marsh plants which have their dormant buds at the 
bottom of the water or in the mud. Somewhat difficult often to separate 
from previous classes. 
Hydrophytes are water-plants with winter buds or rhizomes. 
Therophytes are annual plants — "plants of the favourable season." 
They live through the adverse season as seeds. In Natal it is not necessary 
to distinguish "summer" and "winter annuals." 
Beginning with the Phanerophytes, those classes of growth-forms are 
arranged in a series showing increased protection against the unfavourable 
season. Phanerophytes are characteristic of favourable climatic conditions. 
Therophytes, if they predominate, show desert conditions. 
In the following paper Paunkiaer's main scheme has been adhered to 
with very slight modifications, and consequently Eaunkiaer's statistics and 
conclusions for other countries can be utilised for purposes of comparison. 
Where further subdivision was considered advisable, Raunkiaer has not been 
necessarily followed, seeing that Natal naturally differs from the countries 
in the Northern Hemisphere, to which Raunkiaer's papers refer. 
MEaAPHANEROPHYTES. 
Only slight reference need be made to this class, seeing that very few 
trees in Natal grow over 30 metres (100 ft.) high. 
The Yellow-wood, Podocarpus eloncjatus, reaches a height of 120 ft. The 
other species, Podocaiyus tlimibergii, grows up to 100 ft. These are the 
dominant trees forming the upper canopy of the Yellow-wood Bush of 
Natal (1). 
MESOPHANEROPHYTES. 
These are the trees and lianes which grow over 8 metres (26 ft.). There 
are certain features, which belong more or less to the group as a whole. 
The buds are usually very small and not protected by conspicuous scales. 
In some cases, however, there are large stipules. The wood is usually hard 
