June 14,1924 Leaf Rusts of Rye and Barley in the United States 1125 
Abundant infection was obtained upon Northoscordium (PI. 1, D) while no 
signs of infection were detected on Ornithogalum. Aeciospores from the infection 
on Northoscordium were sown two different times on seedlings of Hordeum 
pusillum and of common barley, Hordeum vulgare , which is susceptible to Puc - 
cinia anomala. Infection resulted only on Hordeum pusillum. Telia obtained 
from these cultures were overwintered and again sown upon Northoscordium 
bivalve and Ornithogalum umbellatum in March, 1921. Infection developed only 
on the Northoscordium. In addition, five different uredinial cultures of Puccinia 
anomala from different localities, while infecting barley varieties heavily, pro¬ 
duced no infection when sown on Hordeum pusillum. It seems evident, therefore* 
that although Uromyces hordei and Puccinia anomala are somewhat closely 
related, they are distinctly different as to host specialization, in both the aecial 
and telial stages. 
These results show that Ornithogalum umbellatum is an aecial host for the leaf 
rust of barley in this country as well as in Russia. The four widely separated 
localities from which the telial collections were made also would indicate that 
this is likely to be the case for this rust generally over the entire country. The 
writers have no evidence at the present time to show that the aecial stage is 
naturally produced, as aecia on this host have never been collected or reported 
in this country. However, it is entirely possible that they may be produced 
but have been overlooked, attention not having been directed to this plant, as 
the r61e of Star-of-Bethlehem as an aecial host was discovered quite recently and 
apparently is not generally known. 
Star-of-Bethlehem may become, if it already is not, of considerable impor¬ 
tance in barley-growing areas because of its tendency to escape from cultivation 
and become a weed. In some places, notably in the Southern States, this plant 
has become a pest almost equal in importance to wild onion (garlic), as far as 
occupying cultivated land is concerned. It is a bulbous plant, coming up in 
the early spring and dying down in midsummer. It multiplies rapidly by divi¬ 
sion of the bulb and may be scattered widely over the field in plowing and culti¬ 
vating. It is obvious, therefore, that its presence in barley-growing areas is 
very undesirable. 
Unlike the leaf rust of rye, the leaf rust of barley has not been shown to over¬ 
winter in the uredinial stage in this country. In consequence, the aecial host 
may be an important factor in the survival and spread of this rust. It must 
be acknowledged, however, that in the two places where the rust has been ob¬ 
served by us to be most severe, Arlington Experiment Farm, Rosslyn, Va., and 
Blacksburg, Va., Star-of-Bethlehem is not known as a weed. 
SUMMARY 
1. The leaf rust of rye, Puccinia dispersa, is able to produce aecia on species 
of Anchusa in the United States. 
2. Anchusa officinalis , and A. capensis are susceptible. Nonnea rosea may be 
infected occasionally with production of pycnia only. The other boraginaceous 
species tested remained uninfected. 
3. Anchusa capensis has been found naturally infected by the leaf rust of rye 
and may become of some importance in the spread of the disease. 
4. Apparently unlike the usual situation in Europe, the teliospores of the leaf 
rust of rye are capable of overwintering, and may germinate the following spring. 
5. The leaf rust of barley, Puccinia anomala, from four widely separated 
localities in the United States has been used in inoculation experiments which 
have resulted in the development of aecia on Ornithogalum umbellatum, agreeing 
with results obtained by Tranzschel in Russia. 
