44 BULLETIN 1380, U. S. DEPARTMENT OF AGRICULTURE 
REDDISH BROWN OR PURPLE LEAF-SPOTS 
A common leaf -spot (Phyllosticta sp.) on mature leaves appears 
during the latter part of the dry season. Small reddish spots de- 
velop over the surface of the leaf or at the margins. The diseased 
area extends inward along the veins, or large areas are affected 
which do not involve the margin. The spots increase irregularly in 
size and may involve large areas of the leaf surface. The spots 
assume a deep reddish brown or reddish purple (PL XVIII, C). 
In late stages the epidermis may become separated. It turns ash 
gray and may be peeled from the tissues beneath. The immediate 
margin of the spot is purplish brown, frequently fading to lighter 
shades for a considerable area around the spot. The affected tis- 
sues in the central part of the spots sometimes fall away, leaving an 
irregular hole in the leaf. The color on the lower side of the leaf 
is usually a uniform reddish brown. The normal functions of the 
leaves are considerably affected, and the result may be a premature 
defoliation. 
The fungus most commonly associated with this leaf-spot is a 
species of Phyllosticta which differs in several details from the 
species previously described. Pestalozzia palmarwm and Diplodia 
theobromae occasionally are found on the spots after the fall of the 
leaves. 
.V disease of more or less common occurrence on mature leaves of 
Hevea takes the form of small or large irregular reddish brown 
spots which frequently involve the margins of the leaves. The fun- 
gus associated with this disease is a Phyllostictina which appears 
to be different from species in this group previously described. 
BROWX LEAF-BLIGHT 
A disease known as brown leaf-blight (Phyllosticta heveae 
Zinini. ), which starts at the tips and extends uniformly over the leaf 
in half or more of its length, is more or less common on young trees 
in dense shade. The affected area at first is a light yellowish brown 
or buff on both sides of the leaf. The color deepens with the ad- 
vance of the infection, and in final stages it is dark brown (PL 
XVIII, D). Phyllosticta heveae is associated with the disease to 
the exclusion of all other fungi. After the leaves fall or after their 
death on the tree Diplodia theobromae may appear. 
This disease has also been found on Hevea in Florida. 
GRAY LEAF-F. LIGHT 
A number of leaf diseases (LeptospTiaeria sp.; Ooniothyrium sp.) 
are confined to rather limited areas of tin 1 leaf surface and cause 
injury by multiplication of the spots, which may become confluent, 
thus eventually affecting large areas. Two leaf diseases more or 
less common on Hevea usually start at the tip of the leaves and 
gradually progress uniformly toward the petioles. Only a small 
portion of the green surface of the leaves at the base remains, or the 
disease may extend only half the length of the leaves. 
A species of Coniothyrium is associated with one of these dis- 
eases. The upper side of the diseased surface is whitish gray and 
