sr 
318 
- THE DICTIONARY OF GARDENING, 
Rosa—continued. 
possibly some of them may be injurious, in their younger 
stages, to living parts of the Rose-plants. The most 
generally hurtful of all the true parasitic Fungi is Rose 
Blight, which is one of the so-called Mildews, and belongs 
to the group of Erysiphee (see Mildew and Oidium). 
Its scientific name is Spherotheca pannosa, but it differs 
_ generically from Erysiphe in little save that in each of 
the minute, black perithecia scattered over the mycelium 
there is only one ascus. In this lie eight oval spores. 
S. pannosa grows on all young parts of plants in the 
form of a dense, pale grey, velvety coat, covering large 
patches of the surface. The parts attacked by it are 
much altered in appearance, the leaves becoming blistered 
and twisted, and the flower-stalks and calyces swollen and 
distorted. An account of the structure of the Fungi in 
this family will be found under the headings quoted 
above. S. pannosa is found to grow also on the Peach. 
The application of powdered sulphur, or of weak solu- 
tion of sulphide of potassium, will destroy the Fungus 
without injury to the host-plant. 
- Another kind of Mildew has been observed on the 
lower surface of the leaves of Roses in conservatories. 
This also forms grey patches, but they are less ex- 
tensive and far less dense than in the former species. 
Irregular, brownish spots appear on the upper surface 
of the leaves; they extend over the leaves, which soon 
wither. These are the work of Peronospora sparsa, 
and bear scattered conidiophores, or slender, branched 
stalks, on which oval conidia are produced, on the tips 
of the branches. No remedy is known for this. Fungus ; 
and all parts that bear it should be cut off and de- 
stroyed. See Peronospora. 
The Rose Rust (Uredo or Lecythea Rose) and the 
Rose Brand (Phragmidium mucronatum) are believed — 
to be forms of a single species of Fungus, the Uredo 
being the summer form of spore, and the Phragmidium | 
the autumn form, or teleutospore. Both forms occur 
scattered in small masses on the lower surface of the 
_ leaves; indeed, they grow on the same patches of my- 
celium ; but the Brand appears later in the season. The 
Rust consists of pale yellow, one-celled, round or oval 
bodies, covered with very fine, prickly warts. The Brand 
is made up of very different spores, since each is formed 
of a row of from four to nine cells, which have a brown, 
warty outer coat. Each spore is borne on a long stalk, 
thickened below; and each ends, at the tip, in a long, 
conical, colourless papilla or outgrowth. This Fungus 
_ is seldom dangerous to Roses; but it renders the leaves 
unsightly. Unfortunately, no cure is known ; hence, it 
is advisable to remove and to burn such leaves as show 
traces of the Fungus, to prevent it from. spreading to 
healthy plants. See Phragmidium. 
Another Fungus that, at times, renders the leaves of 
Roses unsightly, is that known as Asteroma Rose, Lib. 
(Actinonema Rose, Fr.), which forms dark purplish-brown 
spots, with the appearance of fibres radiating from the 
centre of each. In the spots lie scattered, dark pycnidia, 
containing two-celled spores. This Fungus is probably 
only an immature condition of some unknown pyreno- 
mycetous Fungus. To prevent any extension of the 
slight harm done by it, remove and burn affected leaves. 
The leaves are liable to become covered, on the upper 
surface, with a sooty deposit, imperfect conditions of 
species of Capnodium. OC. Persoonii has been recorded 
from Roses on the Continent; but probably the species 
varies. The Fungus grows chiefly in the secretions of 
the Aphides so‘common on Roses; the dark crust ob- 
structs access of light and air to the leaves. The best 
remedy is to get rid of the Aphides, and to clean the 
leaves, and keep them clean by syringing or sponging. 
Insects. In Kaltenbach’s “ Pflanzenfeinde,’ nearly 
100 species of insects are recorded as more or less 
hurtful to Roses, i.e., by feeding upon them as larve or 
Rosa—continued. 
as perfect insects; and to that number many more 
could now be added. Hence, only such as are markedly 
hurtful to these favourite flowers are selected for notice 
here. 
The roots may, at times, be damaged by larve of 
Cockchafers, and other subterranean foes; but these need 
not detain us. The larve of Agrilus viridis feed below 
the bark on stems of Roses, usually close to the origin 
of a branch. The beetles are from lin. to jin. long, 
rather narrow, and brassy-green or blue; they are not 
uncommon in the South of England. : 
The twigs and young leaves are much injured by 
Aphides or Green Flies, of which five species are recorded, 
with descriptions and coloured figures, in Buckton’s 
“British Aphides,’ as feeding on Roses. Of these, 
Fic. 384. APHIS (SIPHONOPHORA) ROSA—a, Line showing 
the natural length. 
Siphonophora Rose (see Fig. 384), S. rosarum, and 
S. dirhoda, are often very plentiful on Sweet Briar and 
on the Cabbage Rose, and also attack the wild Dog Rose. 
Evergreen Roses seem less liable to be injured by them. 
The other kinds of Aphides are less evidently hurtful. 
All of them may be treated in the same way. The reme- 
dies recommended under Aphides will be found useful. 
It is desirable to keep the plants as free as possible 
from. these insects, alike because of the sap they ab- 
stract, and because of their excretions covering the leaves 
and obstructing the functions of the latter, as’ well as 
affording a medium for the growth of dark-coloured 
Fungi, which still further interfere with the welfare of 
the plants. The larve of a small Moth ` (Spilonota 
roborata), and those of a Sawfly (Pecilosoma candi- 
datum), bore into the pith of MRose-branches from 
May to July, of course killing them, and causing the 
leaves on them to wither. The latter insect has 
been observed near Oxford by Prof. Westwood, but is, 
fortunately, rare. The infested branches should be cut’ 
, off and destroyed while still tenanted by the larve. 
The leaves of Rose-bushes are devoured by numerous 
insects, mostly Moths and Sawflies. Of the larger Moths, 
there may be named the Lackey Moth, the Gold-tail 
Moth and its allies (see Liparis), the Vapourer Moth 
(see Orgyia antiqua), the Bufftip Moth (Pygera 
bucephala), the Winter Moth (Cheimatobia brumata), 
and the Barred Yellow Moth (Cidaria fulvata). Each 
of these, save the last, will be found described under 
the headings quoted. Cidaria fulvata is a Geometer, 
about lin. in spread of wings, with a slender body. It 
is yellow, with a broad, brown, angled band crossing the 
front wings, and a pale, triangular spot at the tip, 
bordered below by a short, dark streak. The larve of 
these moths should be shaken or picked off the bushes, 
collected, and destroyed. Those of the Winter Moth 
live between leaflets united by threads of silk. The 
females of this very destructive species are unable to fly, 
