170 
MILDEWS, RUSTS AND SMUTS 
HEMILEIA, Berk, and Broome 
Uredospores. Forming effused, powdery orange patches ; 
spores in small heads or clusters borne at the tips of a cluster 
of hyphae which emerge through a stoma, 3—5 germ-pores 
present. 
Teleutospores. vSpores appearing in the centre of the 
head of uredospores after the latter are mature, i-celled, 
broadly ovate and more or less umbovate, with one apical 
germ-pore ; promycelium cylindrical, stout, 3-septate, 
each cell producing a single subglobose promycelium spore 
on a slender sterigma. 
Closely allied to Uromyces, differing principally in the 
mycelium producing uredospores and teleutospores, emerg¬ 
ing in fascicles or bundles through the stomata. 
An exotic genus, of which two species have been intro¬ 
duced into this country on living orchids. 
Hemihia vastatrix, Berk, and Broome, is the dreaded 
coffee-leaf disease, which has incurred the loss of many 
millions of pounds sterling and rendered impossible the 
cultivation of coffee in Ceylon. The disease is also rampant 
in the coffee plantations in Africa. It has not yet been 
recorded on coffee in the New World. 
Hemileia americana, Mass. 
Uredospores. Forming broadly effused, powdery, orange, 
coloured patches on the under surface of the leaf, spores 
shortly stipitate, globose, v/all with minute, scattered 
warts, 24—32 [JL. 
Teleiitospores. The spores occupy the central portion of 
the heads of uredospores, shortly stipitate, colourless, 
broadly obovate or turbinate, often with a small, obtuse, 
apical umbo, wall covered with minute warts, 30x25 p. 
S3m. Hemileia oncidii, Griff, and Maubl. 
On living leaves of Cattleya dowiana, imported from Costa 
Rica. 
Mycelium is very abundant in the tissues, haustoria are 
absent. 
Mr. Grove has recorded a species of Hemileia from Ire¬ 
land, parasitic on orchids, which he considers to be //. 
phaji, vSydow, but which in reality is H. americana, Mass. 
The uredospores of H. phaji have the free convex portion 
covered with warts, whereas those portions of the spores 
in contact with each other are smooth, as in H. vastatrix. 
On living loaves of Pliajus wallichii. 
