SYNOPSIS OF THE GENUS LONICERA. 31 
division of the genus into the two subgenera, Periclyme- 
num and Chamaecerasus, or as they are usually called, 
Caprifolium and Xylosteum, which form two very well 
defined and natural groups if based on the character of the 
inflorescence and not on the habit. 
The subgenus Periclymenum, which is comparatively 
small and homogeneous, can be divided easily into closely 
related subsections; but the much larger subgenus Chamae- 
cerasus has been subdivided in various and mostly not 
very satisfactory ways. Most botanists take the shape of 
the corolla, — whether the limb is two-lipped or almost 
regular, —as the best character for the subdivision, but 
this difference can scarcely be used to characterize even 
subsections, since it would separate in several cases very 
closely related species, while in other cases the shape of 
the limb is intermediate. It is a character of but sec- 
ondary value, as it has been probably acquired late in the 
genesis of the genus by part of the species of several 
already well differentiated groups as an adaptation to 
certain insect visitors; it therefore would furnish a very 
artificial subdivision without any concomitant characters. 
There is, however, a group of Loniceras with really actino- 
morphous flowers, hitherto confounded with the pseudo- 
actinomorphous species. Only Klotzsch seems to have 
noticed this fact, as appears from a note by A. Garcke 
in Reise des Prinzen Waldemar (1862), p. 86: 
‘‘ Ausser diesen befindet sich in der Sammlung noch 
eine, wie es scheint, von ZL. Myrtillus nicht verschie- 
dene Art, die Dr. Klotzsch neu benannt and worauf 
er eine neue Gattung griindete, deren Namen ich zur Ver- 
meidung unniitzer Synonyme mit Stillschweigen tibergehe.’’ 
The actinomorphous character of the species of Isoxylosteum, 
as I propose to call this section, isnot only shown by the limb, 
but much more markedly by the presence of five nectaries, 
while all the other species have only one to three nectaries at 
the base of the corolla below the lower lip, usually placed 
