144 SOUTH AFRICAN BOTANY 
plants, and are distinguished as total or partial parasites, 
according as they obtain all or only some of their food 
from other plants. The Dodder (Cuscuta) is an example 
of a total parasite, one species of which is parasitic on 
Lucerne in this country. The seed germinates late in 
the spring, when the Lucerne is well established. It 
sends out a little root in the ground, and a thread-like 
shoot into the air, this shoot elon- 
gates rapidly and circles around until 
it comes in contact with the stem of 
a Lucerne plant. It twines round 
this host plant, and sends suckers or 
haustoria into the stem. The xylem 
and phloem of these haustoria fuse 
with the xylem and phloem in the 
vascular bundles of the host plant, 
me ooo and thus the Cuscuta draws all its 
cular Respiration. nourishment from the host. The root 
dies off as soon as the parasite is well established. After 
a time the Dodder produces clusters of pinkish flowers, 
but it never has any green leaves, only small reddish- 
brown scales on its thin red stems. The seeds ripen at 
the same time as the Lucerne seed, hence, when the 
Lucerne seed is gathered, the seeds of this parasite are 
very apt to be gathered with it. 
The mistletoe is a partial parasite; it has green leaves, 
and is therefore able to assimilate carbon di-oxide from 
the air, but it takes its supply of water and dissolved 
salts from the host plant on which it lives. The seeds 
are dispersed by birds, who eat the berries, and deposit 
the seeds on the branch of some tree. There it ger- 
