K NOTR ON INDIAN WHEAT-RUSTS. 
<03 
rendered it impossible to carry the necessary experiments, which 
were initiated by one of us, to completion. As much, however, was* 
done as it was possible, during what remained of the cold season, to 
do. In the meantime it was essential also to ascertain with some 
approach to accuracy whether the phytogeographical area occupied 
by this in any way coincides with that in which wheat is 
grown in India. And as the evidence to be derived from specimens 
of the plant preserved in the Calcutta Herbarium was not conclusive, 
one of us was ordered by the Director of the Botanical Survey to 
visit certain representative wheat-growing districts and to ascertain, 
on the spot, the conditions there as regards the wheat, the rust, 
and the Launea. As some of the results of this investigation tended 
to increase rather than to diminish the difficulties that beset the 
whole problem, it appears better to give an account of these results 
before describing the culture experiments, although as a matter of 
fact the two investigations were being conducted simultaneously, 
Launea asplenifolia DC., the species that was the object of 
this special search, is a member of the natural order Compositasy tribe 
Cichot iaceae § LactuceaSy with an extremely slender and brittle 
perennial rootstock of great length as compared with the size of the 
plant ; this rootstock can be followed almost vertically downwards tc 
a depth of from a feet to 30 inches, without any sensible diminution 
in thickness, but we have never been able to satisfy ourselves that 
the whole rhizome has been obtained ; on being broken the stock 
eludes a-pure white latex, as do the leaves and stems. Towards the 
top the rootstock usually divides into several heads, each head being 
crowned with a rosulate tuft of lyrate-pinnatifid leaves 3—6 inches 
long. These leaves lie close to the ground in plants that grow in the 
open field exposed to full sunshine. When, however, the plant is 
growing in grassy places or amongst thick standing grain some of the 
Internodes of the crown become, as a rule, more or less elongated ; 
giving rise variously to a rosulate arrangement at the base followed 
by a slender stem with scattered leaves above this rosette ; to a stem 
with the leaves scattered throughout ; or to two or more irregular 
rosettes separated by distinct intervals. When growing in grain or 
amongst grass the leaves are delicate and thinly membranous during 
the cold-weather months. When growing in the open, however, the 
leaves are much thicker and firmer, sometimes having an almost 
fleshy consistence, and are, as a rule, paler green in colour. This last 
feature, however, is not at all universal ; at times plants growing 
exposed to the full effects of sun and wind have a dark, purplish red 
tinge imparted to the leaves, especially on the under-surface. The 
