INTRODUCTORY 3 
Colour of stem, leaves, stipules, and bracts may offer valuable 
evidence, as it undoubte ly does in Rubus. Thus, for example, in 
— 
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te) green when mature. avs 
may be dull, shining, or glaucous, dark or pale, besides presenting 
various shades of green, which, though they may defy description, 
may offer valuable points to a careful observer in the field. till, 
as in Rubus, although one may acquire by experience a knowledge 
of the distinctive coloration of the various organs, it is not easy 
to convey these impressions to others by means of written de- 
scriptions; moreover, much of the colour is lost or altered by 
n 
yet it 1s just as common rickles where they 
e stated not to exist as it is to notice their absence when the 
tion does not exclude m al cies have 
descrip : ,m 
their prickles in pairs at the insertion of the petioles, yet this fact 
> & 
those of the flowering-shoots are, as a rule, abnormally small and 
Ww 
Stipules and auricles are almost always described in detail, but 
Some authors of repute, Crépin among others, belittle their im- 
j ns, th isti 
adin 
The form of the stipules, the glandular development on their edges, 
and the direction of the auricles are subject to great variation 
among the individual examples of a species. On the other hand, 
