326 MR. H. H. W. PEARSON ON THE 
In many species the leaves are mostly radical or rosulate; 
those on the upper and more exposed parts of the erect stem 
being few, small, and usually erect. 
A red or purple pigment is very commonly present in the 
leaves—partieularly the young leaves—and youug shoots of 
patana-plants. Diverse and conflicting views as to its functions 
have been advanced (41); here it is possibly important as a 
screen against too intense illumination (40). The pigment is 
usually contained in the cells of the glabrous leaf; less commonly 
a more or less dense covering of yellow or brown hairs (Crota- 
laria sp.) provides a light-sereen as well as a meaus of reducing 
transpiration. 
All stages of hairiness are commonly found on the leaves of 
patana-plants—the most pronounced eases being the densely 
lanate or floccose leaves of species of Anaphalis; in all these 
cases the hairs are more abundantly developed on the younger 
parts. In Knowxia platycarpa, œ small shrub whose adult leaves 
are erect or semi-erect and perfectly glabrous, the young 
leaves bear fugitive hairs. In many cases, particularly in those 
occurring below 4500 feet, the hairs doubtless function as a 
means of reducing transpiration ; above 4500 feet, particularly 
at the higher elevations where the most pronounced hairiness 
oceurs, its use to the plant must be rather as a protection 
against cold, and perhaps more especialy as a means of 
preventing the wetting and consequent blocking of the 
stomata—a function which must be of considerable import- 
ance in an atmosphere so constantly saturated as is that 
of the more elevated portions of the region with which we are 
concerned. 
A hanging position is so common as to be almost normal 
for the young leaves of shrubby species occurring on the lower 
patanas. The delicate tissues thus escape the injurious effects 
of directly incident illumimating and heating rays (42). 
The presence of an ethereal oil in the leaf is a common 
occurrence in the Labiate of the patanas, and more particularly 
in the well-known “ Citronella” or * Mana” grass (Andropogon 
Nardus). This grass is found abundantly from 5000 feet down- 
wards, and frequently forms a belt at the edge of the patana 
parallel with the forest-boundary ; it attains a height of five feet 
or more. In strong sunlight it emits a sickening and almost 
overpowering odour of Citronella oil. The secretion of ethereal 
