476 BOTANICAL GAZETTE [MAY 
plants were examined and all of them were found to be infected; 
some so badly that the leaves were dying, while all (6) of the check 
plants were healthy. At this date pycnia only were present, 
exuding droplets of a sweetish sticky fluid like honey-dew. 
Another trip was made to the Station June 30, 1917, when the 
inoculated leaves showed well developed aecia, while the check 
plants were still free of the rust. These inoculations were not 
considered absolutely conclusive, however, since the Berberis 
plants inoculated were in the open and therefore subject to external 
contamination. 
In the fall of 1916 bulbs of Oxalis violacea were transferred from 
the mountains to Albuquerque, a distance of some 15 miles from 
any Berberis plants, and therefore free from any possible exter- 
nal contamination. Fresh but non-sporulating material of the 
Aecidium on Berberis was obtained from Bear Canyon June 22, 
1917. At this time no Oxalis plants had appeared above ground 
in the vicinity of the infected Berberis leaves in the Canyon, but 
the Oxalis plants transferred to Albuquerque the preceding fall 
were in full leaf. The infected Berberis leaves were moistened and 
kept overnight under a bell jar to start sporulation. On June 23 
two species of Oxalis (O. violacea and O. stricta) were inoculated 
under control conditions with the aeciospores from Berberis. Bell 
jars were kept over the plants 60 hours. Checks were also made. 
On June 30 many of the inoculated leaves of O. violacea had the 
typical uredinia of Puccinia oxalidis, while the check plants as well 
as all plants of O. stricta were free of the rust. July 22 telia were 
present on the inoculated leaves of O. violacea. The inoculations 
here reported, together with those made at the Tejano Experiment 
Station, prove conclusively that the new Aecidium on Berberis 
repens is the alternate stage of Puccinia oxalidis, a description of 
which is herewith given. 
PUCCINIA OXALipIs (Lev.) Diet. and Peck 
O. Pycnia amphigenous but mainly epiphyllous, seated on 
pallid to slightly reddish spots 4-8 mm. in diameter, conspicuous, 
conic-globoid, honey-yellow becoming blackish brown, appearing 
_in the fall of the year when the pycnospores are discharged in a 
