LEAVES 29 
only two come off at the same node, and whorled if more than 
two come off together. : 
Arrangement lhe arrangement of leaves is to some actont 
creas connected with the kind of root. Those plants, 
with Shape like rhubarb, which have tap roots that occupy 
of Roots. but a small space have leaves that turn inwards, 
so that the water which they collect passes down to the centre 
of the plant. On the other hand, in plants that are much 
branched and have spreading leaves, the watershed is such 
that water passes to the circumference of the area to which 
the fibrous roots extend, and then it is absorbed by the root 
hairs. Thus, in a slight shower, it is possible to be quite 

Fic. 29.—Compounp, DiciraTE LEAF oF LUPINE, 
1, lamina ; p, petiole; sh, sheath ; st, stipules, 
sheltered if walking under trees, for the water drips from one — 
leaf to the next below, until the outermost and lowest leaves 
are reached, and then it falls to the ground; the area that 
remains dry is that occupied by the roots. 
Structure ofa 4 foliage leaf usually consists of (1) a sheath ; 
Foliage Leaf. (2) a stalk; (3) a blade. | 
In many leaves the sheath has lateral outgrowths, known 
as stipules. These are sometimes very small, although occa- 
sionally they are very conspicuous ; thus, in a species of pea 
