440 MR. F. O. BOWER ON THE STRUCTURE OF 
On the Structure of the Stem of Rhynchopetalum montanum 
(Fresen.) *. By F. O. Bown, M.A., F.LS. 
[Read December 20, 1883. ] 
(Prates XXXVI.-XXVIII.) 
RHYNCHOPETALUM MONTANUM is a native of Abyssinia, growing 
in districts 11,000 to 13,000 feet above the level of the sea. It 
differs from the allied Zobelias in being a plant which lives 
through more than a single year. The small lanceolate leaves 
first formed are succeeded as the plant grows older by larger 
ones, arranged on a more complicated plan, while the earlier 
leaves are successively thrown off and wither. The stem, which 
meanwhile increases in bulk, is completely covered externally by 
the scars or bases of leaves which have thus been thrown off. 
These scars appear as diamond-shaped areas on the surface of 
the stem, and are covered by a thick layer of corky tissue, in 
which the ends of the vascular bundles of the leaf-trace (five in 
number) may often be clearly seen. As the stem increases in 
bulk, the corky covering is split and fissured, so that the outline 
of the leaf-scars becomes unrecognizable. In this condition the 
old stem is not unlike that of some Cycads in external appear- 
ance. The stem, growing thus for four or five years, gradually 
attains a considerable thickness (a specimen in the museum at 
Kew is about 5 inches in diameter) ; it is columnar in form, and 
is, in most cases at least, unbranched ; it reaches a height of 12 
to 15 feet. 
Internally it is succulent, especially when young; older stems 
are of sufficient hardness and strength to be used in Abyssinia 
for building purposes. 
Axillary buds appear in the axils of the leaves at an early 
stage; but they are not developed beyond the first stages until 
the leaves, in the axils of which they are placed, have fallen off. 
Some, but not all, of them grow actively, developing a tuft of 
leaves, and on their underside often forming roots, which esta- 
blish themselves in the soil. These axillary buds, which often 
appear as though they were of adventitious origin, especially at 
* De Candolle, * Prodromus,’ vol. viii. p. 396. Fresenius, Bot. Zeit. Flora, 
Oct. 1838, p. 603, and figured by him, ‘Museum Senckenberg.” iii. Taf. iv. 
Richard, Flora Abyss. vol. ii. p. 9. Figured from a Kew specimen, Bot. Mag. 
5587. 
