Aerial Roots of Tibouchina Moricandiana, Baill. 
BY 
BERTHA CHANDLER, M.A., B.Sc, 
CARNEGIE RESEARCH SCHOLAR IN BOTANY. 
With Plate XLVII. 
At the Royal Botanic Garden, Edinburgh, a specimen of 
Ttbouchina Moricandiana in one of the plant-houses, under 
conditions of excessive heat and moisture, showed abundant 
aerial roots. As these roots were somewhat abnormal in 
appearance, especially with regard to their branching, I have 
examined them and give here the results, which are of some 
interest, of my investigation so far as it has been possible to 
carry it up till now. 
The roots arise on the upper branches of the plant, 
usually from a node, though this is not always the case (see 
Figs. 1 and 2). In general appearance they are 10 cm. to 15 
cm. in length, brownish green in colour, stiff, distinctly trans- 
versely wrinkled, and variously branched (Figs. 3 to 9). Usually 
they show negative geotropism, hanging from the under side of 
the branches ; occasionally they are para-geotropic. 
As the roots age, they become constricted at their base, and 
gradually wither off from the portion nearest the base towards 
the tip until the whole is withered. This points to a short life 
and no great functional activity. 
To test their capacity it seemed worth while to study their 
development under soil. Some were therefore cut off from 
the tree and placed in fibre in a forcing-house. They grew 
considerably in length, which fact was distinctly noticeable on 
account of the white colour, but they did not branch. 
A shoot was then cut off with aerial roots already developed 
on it, and was placed so that the roots were plunged in fibre in 
[Notes, R.B.G., Edin., No. XX, March 1g09.] 
