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MILDEWS, RUSTS AND SMUTS 
Syn. Uredo e'ffusa, Berk. 
Puccinia ulmariae, D.C. 
Puccinia spireae, Burton. 
Uromyces ttlmarie, Lev. 
On leaves of meadow-sweet —Spiraea ulmaria. 
The spores are variable in form, sometimes only two 
cells are present, superposed as in Puccinia. 
Triphragmium filipendulae, Pass. ; Plowr., lived., p. 219. 
Uredospores. Early form having the spores oblong or 
pear-shaped, reaching up to 35 p in length, orange. Sum¬ 
mer form with orange, scattered, small sori ; spores globose 
or ovate, orange, with a colourless pedicel. 
Teleutospores. Sori circular, scattered, blackish, soon 
becoming powdery: spores subglobose, yellowish, then 
brown, smooth, pedicel rather long, colourless. 
Syn. Uredo filipendulae, Lasch. 
As in Triphragmium ulmariae, the spores are sometimes 
only 2-celled, and are then indistinguishable in appearance, 
or mode of germination, from those of a Puccinia. 
USTILAGINACEAE 
The fungi constituting the present family are all parasitic 
on plants. The mycelium is very delicate, colourless and 
septate, and frequently permeates every part of the host- 
plant, more especially when a perennial or hibernating 
mycelium is present in some permanent part of the host. 
In other instances the mycelium is localised or confined to a 
limited area of the host-plant. Haustoria are present on 
the mycelium of some species. 
The members of the present family are allied to the 
Uredinaceae in some points, the most important of which 
is, that in both families, the resting-spores or teleutospores 
produce, on germination, a promycelium which gives origin 
to promycelium spores. On the other hand, in the Ustila- 
ginaceae the teleutospores originate within special branches 
of mycelium, which become swollen and more or less 
gelatinous, and eventually disappear, leaving the mature 
teleutospores dry and usually forming a powdery mass. In 
the Uredinaceae the spores are produced at the tips of 
specialised hyphae, which usually remain attached to the 
teleutospores at maturity. Uredospores are absent in the 
Ustilaginaceae. The earliest indication of spore formation 
in the Ustilaginaceae is the presence of globose swellings 
in the mycelium, which continue to increase in size for 
some time, such swellings are either formed at the tips of 
