S3 



Euonymus radicans is a small leaved variety with a decumbent habit. 

 This has also numerous highly ornamental sub-varieties. It is real- 

 ized that it would be a great misfortune if a plant so extensively used 

 for borders and hedges, and sometimes trained as a creeper, were to 

 be so severely attacked by disease as to impair its usefulness or 

 necessitate its complete abandonment. 



Mr. E. S. Salmon, f.l.s., of Wye College, has published a full 

 account of the life history of the disease in the Journal of the Royal 

 Horticultural Society \ Vol. xxix^ pp. 434-442. The plate attached 

 (with the permission of the Council of the Society) is reproduced 

 herewith. 



Mr. Salmon is of opinion that the earliest date of the occurrence 

 of the disease in England was in the year 1900, when it was noticed 

 on shrubs of E. japonicus trained against the wall at the east end of 

 the Shelter Terrace in the Madeira Road at Brighton. The disease 

 soon spread to the west end. In 1904 Mr. Salmon himself observed 

 it extremely abundant on plants along the whole sea-front for over 

 a mile. Later it has been found at Bexhill, Hastings, Ramsgate 

 and Dover. At present it is most abundant in the neighbourhood of 

 Portsmouth and Bournemouth, and it is evidently travelling steadily 

 along the South Coast and many places inland.* It is noticeable that 

 the disease is worse in places where the shrubs are growing in 

 shaded and ill-ventilated situations. 



On the Continent it was noticed at Florence in 1899 and in 

 great abundance at Livorno in 1900. Since then it has spread to 

 Austria, Hungary and France. The disease is well known in Japan, 

 the native home of E. japonicus. Mr. Salmon is of opinion that the 

 fungus may have been lately brought to Europe on diseased plants 

 from Japan. This will explain its epidemic character since it is 

 established that a parasitic fungus on reaching a new country 

 attacks its host-plants with exceptional virulence for several years 

 after its arrival. Examples of this are seen in the historic case of 

 the Vine mildew, and also in that of the recently introduced 

 American Gooseberry mildew. 



A peculiarity of the present mildew is the capacity it possesses 

 of persisting by means of hibernation of its mycelium. If the leaves 

 of affected shrubs are examined in the winter months many will be 

 found on which the mycelium persists in the form of definite rounded 

 or irregular patches. The mildew appears able by means of these 

 patches to exist continuously on the evergreen leaves of the 

 Euonymus, to lie dormant through the unfavourable winter months 

 and again produce spores to infect the young leaves in spring. 



In experiments carried out by Mr. Salmon he found the following 

 varieties of E. japonicus to be fully susceptible to the disease : 

 "aureus," " albo-marginatus," " ovatus aureus," " microphyllus " 

 and " President Gunter." E. radicans or its vars. " microphyllus " 

 and "Silver gem" proved also to be fully susceptible, but the var. 



* Mr. Massee, writing on November 10th, 1911, states :— " the Euonymus mildew has now 

 extended along the South Coast to Cornwall, and it has also been met with on the 

 Southern and Western Coasts of Wales. Spraying as suggested has proved effective 

 when commenced in quite early spring before the new shoots appear, coupled with 

 the removal of all fallen leaves." 



