62 FUNGOID PESTS OF CULTIVATED PLANTS. 



Lavender Leaf-spot. 

 Septoria Lavandula (Desm.), PL IV. fig. 77. 



Parasites of Labiate plants under cultivation as garden flowers are 

 v. tv limited. It is now many years since we found Lavender plants 

 with a great number of the leaves attacked by this endophyte, which is 

 not uncommon in France, but which we have not met with again. 



The bleached spots are small on both surfaces of the leaves, mostly 

 rounded, but sometimes irregular, limited externally by a raised purple 

 line. They do not generally exceed one eighth of an inch in diameter, 

 but several spots are often seen on the same leaf. On the upper surface 

 of the spots a f< sw Mack dots are to be discerned, which are the receptacles 

 or perithecia of the fungus. 



The sporules, or conidia, are long and thread-like, straight or curved, 

 and vitv narrow (25 85 x 2 /<) ultimately; when fully matured they are 

 expelled through a pore at the apex of the receptacle. 



This species has been found also in France, Italy, and Madeira. 



C. Syll. iii. 291-4; Cooke Hdbk. No. 1340; Grevillca, xiv. 103, 

 No. 523. 



Lavender is also liable to a sickening disease, or " wilting," but the 

 cause has not been ascertained, and no fungus been found. 



PESTS OF THE SCROPHULARIACE.E. 



It is a singular fact that no important parasite has yet been recorded 

 in Britain for the numerous Scrophulariaceous plants in general cultiva- 

 tion, although many are known abroad. 



The destructive rot-moulds {Peronospora) are represented by at least 

 four species, which attack Antirrhinum, Digitalis, and Veronica, but only 

 Peronospora grisea has been met with on uncultivated Veronica, and 

 l'i ronospora sordida on Verbascum, in this country. 



The three diseases which produce leaf-spot on Mimulus, and the four 

 on Pentstemon, have, with one exception, never invaded our shores, 

 whilst Calceolaria is still unharmed, and therefore, on the whole, we 

 must be regarded as peculiarly fortunate. The exception is in the case 

 of Phyllo8ticta Pentastemonis (Grevillea, xiv. 90) which has produced leaf- 

 spot on one or two occasions in this country. There is also a leaf-spot 

 [Septoria Pentastemonis) with small round white spots on leaves of 

 Pentstemon, known in North America. 



A new fungus disease on Antirrhinum majus of the kind known in 

 America as Anthracnose, produced by Colletotrichum Antirrhini (Stew.), 

 is recorded r< oently as causing elliptical or circular sunken spots on the 



es of that plant in the United States (Journ. li.H.S. vol. xxvi. 

 L901, p. 194). 



DISEASES OF ENDOGENOUS FLOWERING PLANTS. 



For the saki of reference we have kept these diseases together, as they 



BOt plan i]y of outdoor culture, reserving others, which require 



warm houses or stove treatment, for separate notice hereafter, with othor 



