THE WILLOWS OF OHIO. 285 



Salix alba L. White Willow. 



A tree attaining a maximum height of 30 m. with a trunk 

 diameter of 2.5 m. Like Salix jragilis often growing in clumps 

 but when single-stemmed it is taller and more slender and has 

 the trunk continued as a central shaft to near the top. It is not 

 clean like that species but is covered with a brush of suckers. 

 Bark of the twigs and branches yellowish green varying to yellow ; 

 winter buds smaller (4 mm. long) than those of the crack willow, 

 oblong and well filled out. The leaves reach a length of 13 cm. 

 and a breadth of 3 cm., lanceolate, acute, narrowed to the base, 

 closely and finely serrate, sometimes almost entire, grayish or 

 bluish glaucous, pubescent on both surfaces at least till mature, 

 (hair mostly persistent below) with close, fine, appressed, parallel, 

 grav hairs, stipules deciduous ; primary veins close (closer than in 

 5. jragilis), straight, ascending, regular, extending to the margin 

 without branching, secondaries conspicuously regular but often 

 forking like the letter Y. Catkins on lateral branches or some- 

 times supported only by bracts, scales hirsute, deciduous, cap- 

 sules ovate-conic, not more than -1 mm. long, greenish yellow in 

 fruit, obtuse, glabrous, pedicel very short, style short, stigmas 

 thick. 



Salix alba is a European species planted in this country for 

 the same purposes as 5. jragilis. In most parts of the state it 

 does not seem to escape so readily as that species and hence is not 

 quite as common but may be found planted almost anywhere. 



As stated above, most observers have considerable difficulty 

 in separating this species from the preceding. The difficulty is 

 often assigned to their hybridising propensities. But in Ohio at 

 least hybrids are rather rare. I have found that the two species 

 are distinct and separable in nearly all cases though it was only 

 after long study that the ability to distinguish them was acquired. 

 The manuals state that the species in the typical form is rare in 

 this country, the majority of the American forms being the golden 

 osier (var. vitellina). It is certainly true that few of our plants 

 are the typical hairy plant of Linneus but study of the European 

 material at Washington leads me to the conclusion that in Europe 

 the typical form is about as scarce as here. Further the extreme- 

 ly bright yellow twigs and glabrous, half shiny leaves of the typi- 

 cal varietal form are scarcer in this country than the pure alba 

 forms. It seems to me good practice in a series of intergrading 

 forms to draw the line between species and variety close to the 

 variety and to call all but nearly typical varietal forms the species 

 simply, if for no other reason to avoid the use of a trinomial. 



The variety vitellina then, of Salix alba includes those plants 

 with bright golden yellow twigs and branches, and leaves soon 

 glabrous and bright green. 



