On the Hairs of the Tomentum and Ovary in Rhodo¬ 
dendron Falconed, Hook, f., and Rhododendron 
Hodgsoni, Hook. f. 
BY 
ENID M. JESSON. 
With one Figure in the Text. 
1 the tomenta of the leaves of Rhododendron Falconeri , Hook, f., and 
d \ Rhododendron Hodgsoni , Hook. f. (both belonging to the section 
Eu-Rhododendron ), were found to present a different appearance, they were 
anatomically examined during a critical study of the two species. Further, 
seeing that the indumentum of the ovary of R. Falconeri was also found to 
exhibit considerable differences in its character and was variously described as 
‘ hirsutissimum viscosum’ and ‘densely ferruginous woolly’, the investiga¬ 
tion was extended to that organ. The result of this investigation is 
embodied in the following paragraphs. 
I. Leaves. 
The leaves of R. Falconeri are described by C. B. Clarke in Hook. f. 
FI. Brit. Ind. as ‘large, long-petioled, elliptic, ferruginous tomentose 
beneath, very coriaceous ’, and these, as well as those of the following 
species, are figured in Hook. f. Rhododendrons of the Sikkim Himalaya, 
tt. xv and x respectively. A leaf of intermediate age was selected for 
examination, about 18 cm. long and 10 cm. wide. The tomentum itself is 
particularly conspicuous, forming an orange-brown or cinnamon-coloured 
covering, soft and velvety in texture, thickest at the midrib and thinning 
out towards the margin. A portion of this tomentum was scraped off 
and mounted in glycerine jelly containing gentian violet. On examination 
it was seen to consist of hairs made up of a delicate network of cells in the 
form of a funnel, the uppermost cells of which elongate, forming branches 
or chains of thin-walled cells (Fig. A ), the branches being composed of 
a single row of cells. Frequently individual cells become more or less 
inflated, approaching a more spherical outline, but as a rule they are elliptic- 
ovate. The hairs stand at right angles to the surface of the leaf, so that 
sections cut parallel to it reveal a number of hairs in transverse section, those 
[Annals of Botany, Vol. XXIX. No. CXVI. October, 1915.] 
