Journal of Agricultural Research 
Vol. II, No. 4 
306 
(2) The second series of tests came so late in the season that it was 
either too hot in the greenhouse to infect the Pentstemon or the telial 
material had lost its ability to infect this unusual host under the existing 
conditions. 
The writer used two species of Pentstemon in the culture experiments 
for 1913 and 1914, Pentstemon laevigatus from Virginia and Pentstemon 
tubiflorus from Texas. Only the former was infected by either Puccinia 
andropogonis or Puccinia ellisiana . When the leaves of Pentstemon 
laevigatus are first formed, they are covered with many small deciduous 
hairs, which fall off as the leaf gets older and leave the upper surface of 
the leaf nearly smooth. The leaves are usually not susceptible to either 
rust until after these hairs have disappeared. When the leaves get very 
old they lose their susceptibility entirely. 
There is also often found intermixed with the usual form a strain of 
Pentstemon laevigatus , which retains its hairiness and is at all times 
immune to the rust. 
During the spring of 1913 the writer continued the experiments re¬ 
ported for 1912 1 with Puccinia ellisiana and Uromyces andropogonis 
Tracy and also carried on culture experiments with Puccinia andropogo¬ 
nis and a Puccinia from Oklahoma on Andropogon furcatus , whose secial 
host proved to be Oxalis stricta . Only the results obtained from Puc¬ 
cinia ellisiana and Puccinia andropogonis are given and discussed here. 
To show clearly the pedigree of each lot of teliosporic culture material 
used in the experiments, the secial ancestral host for each year is given in 
the second column of Tables I-IV under the heading ‘ ‘ iEcial ancestral 
host.” 
The teliosporic material used in all the experiments here recorded was 
on Andropogon virginicus t and the inoculations were made under control 
conditions in the greenhouses of the Department of Agriculture at Wash¬ 
ington, D. C. 
Table I .—■Teliosporic culture data for Puccinia ellisiana and P. andropogonis 
PUCCINIA ELLISIANA 
Species inoculated. 
AScial ancestral host. 
Date 
of inocu¬ 
lation. 
Degree of infection. 
Pycnia. 
JEcia. 
Viola tricolor (cultivated 
pansy). 
Viola sororia. 
Do . 
Viola sagittata. 
Viola papilionacea. 
1913. 
Apr. 7 
Mar. 30 
Mar. 34 
Apr. is 
Mar. so 
Mar. 34 
Mar. 38 
...do.... 
Very vigorous. 
Good. 
1913* 
Apr. is 
Apr. 1 
Apr. 7 
Apr. 32 
Mar. 28 
Apr. 3 
Apr. 7 
...do.... 
19x3. 
Apr. 21 
Apr. 14 
Do. 
Apr. 30 
Apr. 3 
Apr. 14 
Apr. 16 
Apr. is 
Do . 
..... do. 
Fair. 
Do . 
.do. 
Only one sorus. 
Viola sagittata. 
.do. 
Good. 
Do . 
.do. 
Viola hirsutula . 
.do. 
Fair. 
Violf 1 pf'data . _ 
.. ..do .. 
Mar. 30 
Mar. 34 
Mar. 28 
No infection. 
Do . 
.do. 
___do. 
Do. 
1 Long, W. H. op. cit., p. 164. 
