July 13, 1893. ] 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
35 
Attacks of parasitic fnngi commonly cause a similar twisting. In this 
district, Poppies, which are extremely common in the cornfields, are 
frequently attacked by a Peronospora (an ally of the Potato fungus), 
and this attack causes the flower stems to become twisted into inextri¬ 
cable knots with the flowers and seed vessels pointing downwards as 
frequently as upwards, or involved in the knots of the twisted stems. 
An example of a Carnation stem, swollen in the middle and with 
leaves twisted with disease, is illustrated in fig. 5. The disease spots 
are white and semi-transparent; when held to the light the inner 
substance of the leaves is seen to have been eaten away. If a small 
portion of the leaf, taken from the neighbourhood of the disease spots, 
is placed under the microscope, eel worms young and old, and male and 
female, with a vast number of eggs, will be seen as illustrated at 
A, B, and c. In a diseased Carnation plant these minute animals exist 
apparently in uncountable numbers. The name of the eelworm is Tylen- 
chus devastatrix, KiiTin. The minute transparent eggs, with the young 
coiled up inside, are shown at A, and the young just emerged from the 
eggs at B, enlarged 200 diameters. An adult female example is 
shown enlarged to 100 diameters at C. The male differs slightly from 
the female, but for all practical horticultural purposes the illustration 
will answer for both sexes. In some eelworms the sexes differ greatly 
from each other in general form. I have grown Carnations from a 
single diseased plant for eight years in succession ; every season the 
old plants have been burnt and new plants secured from layers 
apparently free from disease, yet every season the new Carnation plants 
have swarmed with eelworms. The plants become equally diseased in 
the open garden and greenhouse. This fact shows how necessary it is 
when plants once become infested to entirely destroy them, every frag¬ 
ment from a diseased plant seems to bear the eggs of the eelworm (or 
Nematode) in its tissues. The minute animals live and breed chiefly 
inside the leaves, and the transparent spots are caused by the tissues 
being eaten away. The worms are easily destroyed by caustic solutions, 
but as the creatures live within the stem and leaves it is almost 
impossible to get at them. The attack of eelworms or threadworms 
frequently comes from infested earth or water, and plants are at 
once attacked by Nematodes if grown in earth containing chopped up 
diseased material or if watered with water in which infested plants 
have been broken up and introduced. Tylenchus devastatrix is common 
in a living state in dung; the animal infests Clover and Grasses, and 
passes in a living state and uninjured through the intestines of sheep, 
oxen, horses, and other animals. 
Mr. John J. Willis has experimented with success at Harpenden on 
infested Clover fields, but experiments made on acres of land seem 
hardly applicable to a limited number of Carnations in a flower garden. 
Mr. Willis, as reported by Miss E. A. Ormerod, found that sulphate of 
ammonia and sulphate of potash together at the rate of 4 cwt. per acre 
acted most effectually. Sulphate of iron at the rate of 2 cwt. per acre 
caused the attack of Tylenchus to cease, but half this amount did not 
entirely check the attack. Infested earth can be successfully treated 
with gas lime—see the leaflet by the late Dr. Aug. Voelcker on “ Com¬ 
position and Uses of Gas Lime,” published by the Royal Agricultural 
Society of England. For other methods of treatment see the number 
of the Journal of Horticulture already quoted. This disease was first 
noticed in this country in the autumn of 1881, and an illustration 
and description was published in the “ Gardeners’ Chronicle ” for 
December 3rd, 1881. 
The disease caused by a parasite fungus named Helminthosporium 
echinulatum, H., has been known since 1870, when a description and 
small illustration was publishsd in the “ Gardeners’ Chronicle ” for 
March 19th, of that year. It was again illustrated in greater detail in the 
same journal for August 2l8t, 1886. A fragment of a Carnation leaf 
attacked by the Helminthosporium (a brown fungus mould), is illustrated 
natural size at D (fig. 6). It will be observed that the fungus grows on 
both sides of the leaf in a concentric fashion; a minute spot first 
appears, next a ring round that spot, then a larger ring, one outside the 
other, till in bad cases the rings become confluent and the foliage is soon 
utterly destroyed. The fungus in a fruiting state is superficial, but the 
mycelium, or spawn from which the fungus arises, is partially within the 
membranes of the leaf. The parasite, of course, lives by abstracting and 
living upon the vital juices of the host plant. The fungus itself as seen 
under the microscope and enlarged 300 diameters is shown at E. It bears 
a vast number of jointed spores ; at first these spores are simple or with¬ 
out joints, but at length each spore becomes divided into from two to 
six parts, the spores are faintly brown in colour and covered with 
almost invisibly minute spines. At maturity the spores break to 
pieces at the joints, and every fragment is capable of reproducing 
the disease. These fragments are doubtlessly carried in the air in 
millions, and many probably hibernate in the open ground through the 
winter. They certainly hibernate in greenhouses, Sometimes this 
Helminthosporium infests Sweet vv illiams, and a fungus not to be dis¬ 
tinguished from the Carnation fungus frequently grows on Ornitho- 
galum and perhaps other plants. The parasite is a close ally of the 
fungus which causes the worst form of Tomato disease. Hand-picking 
of diseased leaves has been recommended as a remedy. As the parasite 
lives partly within the leaf it is most difficult to get at, although spray¬ 
ing with a fungicide might stop its growth; the safer and more effectual 
Potato fungus solutions might also be tried. The almost unlimited 
power of spore production in the Helminthosporium makes its position 
almost unassailable. 
The third parasite illustrated at P is as destructive as the other two. 
The fungus which causes the mischief is known as Uromyces 
caryophyllinus, Schreet, It is illustrated natural size at F. I have 
known it and its effects for many years, but I think this is the first time 
it has been illustrated in this country. The fungus is an ally of the 
Hollyhock fungus and the red rust of corn. It grows wholly within the 
leaf, which it distorts, and it ultimately bursts the membrane of both 
sides for the emission of the spores. A small fragment of a Carnation 
leaf attacked by Uromyces is shown in section at G, enlarged 50 diameters 
to show the spore pustules rupturing the leaf membranes above and 
below. Two sets of spores are produced. The spores illustrated at 
H, enlarged 300 diameters, are called Uredo spores, these are orange in 
colour and covered with minute spines, they are produced in inconceiv¬ 
able numbeis and quickly germinate upon Carnation leaves. The germ- 
tubes from the spores gain access to the interior of the leaves by the 
stomata and then quickly form new pustules. This process is repeated 
till in bad cases all the foliage is involved in disease. Towards the end 
of the flowering season resting spores are formed as illustrated at i, 
enlarged 300 diameters. These resting spores are somewhat darker in 
colour than the Hredo spores ; they are furnished with a much thicker 
FIG. 6.—CAENATION FOLIAGE ATTACKED BY HELMINTHOSPOEIUM (D) 
AND UEOMYCES (F). 
membrane or skin, and are smooth. The resting spores hil^rnate 
through the winter in dead Carnation refuse, and germinate in this 
decaying material in or on the ground in the spring, at which time they 
make their attack on previously unaffected Carnations. In greenhouses 
the fungus grows continuously all through the winter by its Uredo 
spores; it however frequently produces resting spores in the same 
pustules with the Uredo spores. This latter fact shows how necessary 
it is to burn or deeply bury all disease-infected garden material. 
Uromyces caryophyllinus is not confined to the Carnation—Dianthus 
Caryophyllus, but occurs on D. supeibus and D. prolifer. 
As this fungus grows entirely within the plant attacked, it is 
obviously most difficult to reach either by sponging or spraying. It is 
reported that the ravages of the Potato fungus as well as of other fungi 
whose habit is to grow within the tissues of the host plant have been 
checked by spraying : if the reports are correct similar good results 
might follow the spraying of diseased Carnations. If diseased and 
dying plants cannot be saved, disease can be prevented from spreading 
by clean gardening, plenty of air in greenhouses, and the destruction of 
all tainted material. If a plant attacked by Uromyces is placed in a 
greenhouse the disease will at once spread with terrible rapidity to 
other plants in the house. Mr. Mai tin K. Smith informs me that this 
fungus seems powerless w’ith him out of doors, and that varieties v/ith 
exceptionally blue foliage resist its attacks. Mr. Smith says that 
