TREES AND SHRUBS 



foliage, but not often in such numbers as to be a pest ; larva of more 

 than fifty species of Saw-flies (chiefly of genus N'ematus) also attack foliage, 

 many being Gall-makers. Stems of Sallows bored by larvae of Osier Hornet 

 Clearwing {T'rochiUum crabi-oniforme). Wood bored by Goat Moth (Cossus 

 ligniperda). 



Grt//*.— I^arge swellings on twigs caused by larva of a Gall-gnat {Cecidomyia 

 salicipei-da) ; I^eaves distorted by larvae of Hormomyia caprea {C. cap?'ea), also 

 galled by a Mite {Eriophyes tetanothrix) ; Pea Galls formed by Ncmatus 

 pedu7icuii and others. 



Fungoid Pests: — Sulphury Wood Rot {Polyporus siilfm-eus), Sooty Mould 

 {Fumago vagans), Goat Willow Rust {Melampsoi'a farinosa). Willow Leaf 

 Blotch {Rhytisma salicinum). 



GRAY SALLOW, Salix dnerea. 



Moist situations. April, May, and again in September. 



Floxvers dioecious, appearing before leaves ; Catkins less thick and silky 

 than Common Sallow, opening later ; 3Iales, Stamens 2, pubescent at base, 

 anthers pale yellow, scales velvety ; Females, peduncle densely velvety ; 

 Ovary silky, style half as long as scales, stigma short ; Fruit a capsule, small, 

 narrow. 



Leaves alternate, variable, elliptic-lanceolate to oblong-obovate, undulate, 

 serratulate, acute or shortly acuminate, pubescent above, glaucous, with reddish- 

 brown hairs beneath, venation prominent both surfaces ; petiole pubescent, 

 dilated below, 2-5 ins. long, 1-2 ins. broad ; stipules large, half-reniform, 

 serrated . 



A deciduous tree, 20-30 ft. ; Stem erect ; Twigs tomentose, passing to 

 smooth, tawny ; Buds large, ovoid, pilose. 



Native of Britain. Foliage attacked by Willow Leaf -spot (Septoria salicieola) 

 and Goat Willow Rust [Melampsora farinosa). Twigs distorted by larvae of 

 Gall-gnats {Cecidomyia salicis and Agromyza schinei'i). 



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