LOBED LEAVES IN MAIZE 
Two Edges of Leaf Cut Each Other When Growing—Resultant Clefts Were 
Supposed by Blaringhem to be Due to Inheritance of a Mutilation 
J. H. Kempton 
Bureau of Plant Industry, Washington, D. C. 
variety of maize from Russia what 
was thought to be a new abnor- 
mality. This was a pronounced 
lobing of the leaves on many of the 
plants, and as none of the grasses 
normally has lobed leaves, this char- 
acter received careful attention. 
As the season progressed, the abnor- 
mality was found in varying degrees on 
all of ninety varieties planted that 
season at Lanham, Md. The con- 
spicuous nature of the lobes led to the 
belief that this must be their first 
appearance. This view was quickly 
dispelled when upon examining com- 
mercial plantings of local varieties 
many of the plants were found to have 
lobed leaves. In following seasons lobes 
recurred not only in Maryland, but in 
many other localities where oppor- 
tunity for examination was presented. 
They were also found on plants of 
Euchlaena, Coix, Tripsacum and various 
members of the Andropogonee, and 
doubtless occur on many other grasses. 
The superficial resemblance of lobes 
to torn leaves must account for the 
fact that they had escaped detection in 
previous years. Careful observation, 
however, reveals pronounced differences 
between lobed and split leaves, and 
once these are recognized, there can be 
no confusion of the two forms of injury. 
The lobes are usually paired, one on 
each side of the leaf and nearly opposite. 
This is not always the case, however, 
as several leaves with only one lobe 
have been found and a few with as 
many as six lobes. 
The most constant characteristics of 
true lobes are the margins, which are 
transparent like those of a normal leaf, 
and are beset with long brittle hairs and 
a double row of short saw-like teeth 
508 
|; 1911 there appeared in an early 
directed toward the apex of the leaf. 
The edges of torn leaves lack these 
teeth and the marginal cells are dead. 
Lobes are also sometimes spatulate in 
form, with the margin at the base of 
the split thickened and rounded. 
The veins frequently divide a short 
distance below the split, one branch 
continuing to the main blade, the other 
to the lobe. The veins that do not 
divide alter their course below the split, 
making a curve which enables them to 
reach the lobe. The presence of normal 
marginal tissue, together with the blunt 
or spatulate form of many of the lobes, 
indicates that the formation of the 
lobes takes place at a very early stage 
in the development of the leaf. 
The lobing often results in a complete 
entanglement of the leaves, so that the 
plant is prevented from growing in 
a normal manner and in extreme cases 
the upper leaves and tassel never 
emerge. Plants thus affected have a 
characteristic ‘‘bent over’ shape. 
LOBING OF OTHER ORGANS 
The occurrence of lobing is not con- 
fined to the leaf blades of the main 
culm and tillers, but has also been fre- 
quently observed on other homologous 
organs of the plant. The most common 
among these are the husks, husk leaves, 
and the glumes of the tassel. In this 
latter case the lobes are very small, but 
are undoubtedly of the same nature as 
those on the leaf blades. 
A slightly modified type of lobing is 
also found on prophylla. The abnormal- 
ity in this case could hardly be called 
lobing, but isin reality notching. These 
notches are in pairs on opposite sides of 
the prophylla, much the same as the 
lobes on the blades. 
Lobes approximating in shape those 
