Anatomy and Physiology of Baccharis genistelloides 
By Extste M. Kuprer 
Baccharis genistelloides Pers. is an inhabitant of the mountains 
of Peru, growing in dry places at an altitude of about 1200 me- 
ters. It has several well-marked varieties which apparently spread 
north into Ecuador, and south and east into Brazil. The typical 
form is a slightly shrubby plant of extremely peculiar appearance. 
The leaves are atrophied, being represented by minute scales 
scarcely more than 2 mm. in length; and the work of photosyn- 
thesis is assumed by conspicuous wings which stand at three 
equal angles from each other. The scales are arranged in three 
orthostichies, and two wings originate from the base of each scale. 
One of these wings runs through only one internode and termi- 
nates at the margin of the scale below; the other, in each case, 
runs through two internodes until it is similarly stopped. This 
alternation ‘of a long and a short wing in each orthostichy, as 
well as the fact that the wings (following the phyllotaxy) twist 
spirally, accounts for the curious appearance of the plant repre- 
sented inf 7. 
While the shoot is almost uniformly leafless in the upper por- 
tion, usually one, two, or even several normal leaves are to be 
found near its base. They are of moderate size, obovate and 
somewhat thickened (f7 2 and 3). The genus Baccharis is a 
large, and as far as leaf-form is concerned, a heterogeneous one. 
The leaves of many species, ¢. g., B. floribunda and B. trinervis, 
are large, thin and smooth; others, as those of 4. a/pina and 
B. microphylla, are minute and thickened ; B. aphylla and B. gra- 
cilis have only narrow phyllodes; and, finally, B. genistelloides 
and B. fastigiata are devoid of foliar leaves. The leaves of sev- 
eral of the species, however (and it is significant that these are 
generally South American species), particularly 4. dioica and 
B. cassinaefolia, closely resemble in shape, size and texture the 
juvenile leaves of B. genistelloides. There is every reason, then, 
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