MODES OF GROWTH 115 
2. Plants with Radical Leaves only : 
(a) Rosette-plants—e.g., dandelion. The daisy is really 
a cushion-plant, but the stems have sunk below the level 
of the ground, producing on the surface a number of 
distinct rosettes. 
(6) Some bulbous geophytes—e.g., crocus, wild hya- 
cinth. 
3. Plants with both Radical and Cauline Leaves : 
(a) Most biennials. 
(6) Some herbaceous perennials—e.g., oxtongue (Hel- 
minthia echioides), rock-cress (Arabis), and some hawk- 
weeds. 
(c) Grass-like plants with tufted habit—e.g., tussock- 
grasses, like Aira flecuosa and Holcus lanatus, and some 
sedges. 
II. Epiphytic Plants, perched on Trees (see p. 121). 
Except in geophytes, these differences of habit are due 
to the many and varied methods adopted by plants to 
secure for themselves an adequate amount of sunlight. 
Leaves, as the chief assimilating organs, seek to take the 
most favourable light - position. Trees effect this by 
lifting up, on tall trunks, a crown of foliage above the 
surrounding vegetation. Plants with prostrate trailing 
stems thread their devious ways among the lower vegeta- 
tion, seeking out favourable spots where their leaves may 
catch the light. The creeping habit of long frail stems 
leads to the scrambling habit, in which the stems hook 
and catch on to other plants, scrambling over their backs 
into the light. From the scrambler to the climber is a 
short step. Epiphytes make their light-position secure 
by perching on the elevated branches of trees. 
Climbing Plants.—These have long weak stems, and 
solve the problem of reaching a position of advantage by 
climbing up the bodies of other plants. They derive no 
nourishment from the supports upon which they lean, 
although occasionally they injure them by intercepting 
the light which properly belongs to them. Climbing 
plants were divided by Charles Darwin into the following 
groups : 
1. Seramblers, or Hook-Climbers.—These are the least 
specialized of climbing plants, and are not far removed 
