SALIC ACE^E 167 



authesis, becoming orange or purple; ovary sessile or stipitate, conical, obtuse to 

 subulate-rostrate, glabrous, tomentose or villous, with an abbreviated style divided 

 into 2 short recurved retuse or 2-parted stigmas; ovules 4-8 on each of the 2 

 placentas. Fruit an acuminate 1-celled capsule separating at maturity into 2 re- 

 curved valves. Seeds minute, narrowed at the ends, dark chestnut-brown or nearly 

 black ; cotyledons oblong. 



Salix inhabits the banks of streams and low moist ground, the alpine summits of 

 mountains, and the Arctic and sub-Arctic regions of the northern hemisphere, ran- 

 ging southward in the New World, with a few species, through the West Indies and 

 Central America to the Andes of Chili, and in the Old World to Madagascar, 

 southern Africa, the Himalayas, Burmah, the Malay peninsula, Java, and Sumatra. 

 Of the 160 or 170 species which are now recognized about seventy are found in North 

 America. Of these twenty-one attain the size and habit of trees, the others being 

 small and sometimes prostrate shrubs. Of exotic species, Salix alba, L., and Salix fra- 

 gilis, L., important European timber-trees, are now generally naturalized in the 

 northeastern states. The flexible tough branches of several species are used in mak- 

 ing baskets; the bark is rich in tannic acid and is used in tanning leather and yields 

 salicin, a bitter principle valuable as a tonic. Many of the species are cultivated 

 as ornamental trees. 



Salix is the classical name of the Willow-tree. 



CONSPECTUS OF THE NORTH AMERICAN ARBORESCENT SPECIES. 



Scales of the aments of uniform color ; amenta usually on leafy branches. 

 Stamens 3 or more ; aments terminal. 

 Petioles without glands. 



Leaves green on both surfaces, narrowly lanceolate, long-pointed, often falcate. 



1. S. nigra (A, C, E, G, H). 

 Leaves pale below, lanceolate or ovate-lanceolate. 



Leaves silvery white below, short-petiolate. 2. S. longipes (A, C, H). 



Leaves pale or glaucous below, slender-petiolate. 



3. S. amygdaloides (A, B, F). 



Leaves pale blue-green, lanceolate to oblong-lanceolate, acute or acuminate, minutely 

 denticulate or nearly entire, coriaceous, subperjistent. 



Leaves pale or glaucous below. 4. S. laevigata (G). 



Leaves of ten -falcate, silvery white below, distinctly serrulate. 



f>. S. Bonplandiana (H.) 

 Petioles glandular ; leaves lanceolate, taper-pointed. 



Leaves pubescent as they unfold, pale or glaucous below. 



6. S. lasiandra (B, F, G). 

 Leaves glabrous, coriaceous, dark green and lustrous above, pale below. 



7. S. lucida (A). 

 Stamens 2 ; aments terminal and axillary ; leaves linear-lanceolate. 



Leaves denticulate, usually green on both surfaces, mostly glabrous. 



8. S. fluviatilis (A, B, C, E, F, G, H). 



Leaves entire or nearly so, light yellow-green, villous below, with lustrous pale 

 hairs. 9. S. sessilifolia (B, G). 



Leaves small, entire or nearly so, pale gray-green and puberulous. 



10. 6. taxifolia (H). 



Scales of the amenta dark-colored at the apex ; aments on short branches, with leaves 

 usually reduced to scales ; stamens 2. 



