A New Variety of Koeberlinia 
E. R. Bocuscu 
Field studies of Koeberlinia spinosa Zuccarini have revealed 
variations unmentioned in literature. The author’s attention has 
repeatedly been drawn to a decidedly slender form that differs 
from the species by its more diffuse habit and greater ramifica- 
tion of branchlets. Numerous intergradations have been encoun- 
tered, and because of ecologic as well as taxonomic considera- 
tions these variations seem justly to be considered as stable. 
Dr. Asa Gray was evidently acquainted with a few of these 
forms. Although he does not specifically mention these variations 
in his Synoptical Flora when he describes Zuccarini’s species, the 
description is, nevertheless, broad enough to be inclusive of some 
variability. To a certain extent this is also true of Small’s descrip- 
tion in the Flora of the Southeastern United States. 
The botanist in the field, working in the region in which this 
Species occurs, may be surprised that such active collectors as 
Wright, Nealley, Palmer, and Rose failed to account for these 
odd forms. However, the wide geographical range of the species, 
the seasonal differences in time of flowering, the lack of compara- 
tive herbarium material, and the physical difficulties involved in 
such field work serve to satisfactorily explain this apparent dis- 
crepancy, 
The plant upon which Zuccarini evidently based his species is 
widely distributed through western and southern Texas, New 
Mexico, and Mexico. It flowers uniformly from June to August, 
the period being locally dependent upon summer rainfall. 
The variety here proposed as new, seems to flower only a 
March and April and then very sparingly. It has been the writer’s 
good fortune to be able to actually cover much of the natural 
range of the species. However, until the fall of 1930, he was un- 
aware of the existence of flowering material, for usually the field 
Work was undertaken after the end of May. In the course of work- 
mg over a collection made by Mr. Fred Warren along the Rio 
rande River while he was with the U. S. Biological Survey, a 
mature flowering specimen was discovered. í 
This new variety cannot be considered as a mere ecad. Its in- 
dependence of environmental factors is too pronounced; also it 
may be found on open hills as well as in dense chaparral, freely 
mingling with the species. Likewise, it is not a distinct species, 
°F with a little diligent search every intergradation between the 
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