244 SIR JOHN LUBBOCK ON THE FORM OF THE 
On the Form of the Leaf of Viburnum Opulus and V. Lantana. 
By the Rt. Hon. Sir Joun Lusyock, Bart., M.P., E.R.S., 
DCL. LED., EES. 
[Read 20th February, 1890.] 
We have in this country two wild species of Guelder Rose: 
one Viburnum Lantana (usually known as the Wayfaring Tree) ; 
the other Viburnum Opulus. They frequent woods, especially in 
chalky districts ; but, though very nearly allied, their leaves are 
remarkably different. I extract the following descriptions from 
Syme * :— 
Of V. Opulus he says :—* Leaves deciduous, stalked, roundish 
in outline, 3-lobed, with the lobes acuminate, coarsely toothed 
and ciliated, finely pubescent, but not furfuraceous beneath. 
Petioles with adnate stipuliform appendages in the form of 1 
(or sometimes 2) linear processes on each side a little above the 
base.” There are, I may add, two or more honey-glands at the 
base of the lamina of the leaf. 
Of V. Lantana he says :—“ Leaves very shortly stalked, with- 
out stipules, ovate-oval or elliptical-oval, dentate-serrulate, 
deciduous, rugose, furfuraceous-pubescent beneath, especially on 
the veins, at length nearly glabrous.” There are no honey- 
glands. 
No attempt, so far as I know, has been made to account for 
the difference in form of the leaf in species so nearly allied ; 
for the presence of the honey-glands in the one and not in the 
other: nor to explain the reason for the existence of the peculiar 
filiform stipuliform appendages; nothing exactly resembling 
which occurs in any of our other forest trees, the nearest approach 
being in the allied genus Sambucus. The presence of stipules 
in Viburnum would be the more remarkable, as in the family 
Caprifoliacez, to which the Viburnums belong, stipules (if they 
be stipules) are confined to this genus, to Pentapyæis and to 
Sambucus. 
There are many cases where, among allied species, some have 
stipules and others have not. Thus among the Alsineæ stipules 
are present in Spergula and Spergularia, and amongst the Poly- 
carpeæ, while Alsine, Stellaria, Cerastium, and others have none. 
* In Sowerby’s ‘ English Botany,’ 3rd ed. iv. pp. 202 and 203. 
