WILLOWS 245 



tipped teeth, and tapering sub-sessile base. When young 

 densely silky, but may be later glabrescent and greyish 

 green above and silky-pubescent beneath; the hairs 

 parallel with the midrib. Stipules small, lanceolate, pu- 

 bescent, caducous: petiole short, 8 12mm., eglandular. 

 Stomata almost as numerous above as beneath. Autumn 

 leaves yellow and brown. 



Venation fine and pinnate reticulate, the curved 

 secondaries coming off at open angles and breaking up 

 before reaching the margin, the long axes of the meshes 

 oblique. Tertiaries numerous and tend to form cross-ties. 

 Secondaries fairly long, especially in the middle of the 

 leaf. Margin not reflexed, serratulate. Upper surface 

 dark green, lower white or greyish, and silky. 



[The direction of the silky hairs, parallel with the 

 midrib and not with the secondaries, distinguishes this 

 species from 8. viminalis. See p. 286. 



Certain varietal forms with characteristic colours of the 

 twigs are noteworthy, of which S. vitellina, L., the Golden 

 Osier, with golden yellow twigs, and 8. ccerulea, with olive 

 green twigs and bluish leaves, both grown as osiers, are 

 the principal. 



The chief difficulty is with 8. fragilis and allied forms, 

 or varieties, such as 8. Babylonica, 8. Russelliana, &c., 

 especially when the leaves are old and nearly glabrous. 

 8. fragilis is typically glabrous and greener, and its twigs 

 snap at the articulations. 8. Russelliana has the glabrous 

 leaves of 8. fragilis, but the twigs hardly fragile ; and 

 8. Babylonica has narrower glabrous leaves and the weeping 

 habit. 



8. rubra, Huds., is a variety or hybrid of 8. purpurea, 

 with lanceolate and often sub-opposite leaves, silky beneath, 

 and about 6 7 times as long as broad (9 18 x 2 3 cm.); 

 in one form known as the Rose Willow, owing to the pink 

 bud-galls often borne by it. 



