66 WILLOW FAMILY 



Trees and shrubs; scales of the catkin entire or merely toothed. 1. Salix. 

 Trees; scales deeply cut; leaves ovate or roundish 2. Populus. 



1. SALIX. Willow. 

 Winter buds covered by a single scale. Catkins appearing 

 with or before the leaves, their scales not deeply toothed. 

 Stamens 1 to 10. 



A. Stamens 3 to 9; filaments hairy; leaves mostly 3 to 7 in. long-; 

 slender trees. 



Petioles glandular at summit; leaves Vi in. or more wide. 1. 5. lasiandra. 

 Petioles not glandular; leaves narrower, mostly curved... 2. 5". nigra. 



B. Stamens 2 or 1; shrubs, rarely tree-like. 



o. Creeping shrub, rooting at the joints 11. 5. arctica. 



b. Narrow-leaved shrub of low altitudes; leaves x /& to }4 



in. wide, \Yi to 5 in. long; peduncles short, leafy; 



filaments hairy 3. 5". longifolia. 



c. Narrow-leaved shrub; leaves silvery-silky beneath, 



mostly green above ; stamen 1 4. 5". sitchensis. 



d. Erect shrubs and trees; leaves wider in proportion 



(except no. 8); stamens 2. 

 Peduncles short, not leafy-bracted. 



Catkins nearly globose; leaves glabrous 12. 5. monica. 



Catkins cylindric; leaves pubescent when young. 



Capsules silky; leaves obovate 5. 5". scouleriana. 



Capsules glabrous 6. S. lasiolepis. 



Catkins cylindric; leaves glabrous. (See no. 7.) 

 Peduncles evident, leafy-bracted; mostly of over 6,000 

 ft. alt. 

 Capsules and mature leaves glabrous; stigmas notched. . 7. S. cor data. 

 Capsules pubescent. 



Twigs white; leaves small, narrow, silvery-pu- 

 bescent 8. S. tnacrocarpa. 



Twigs green, brown, or yellowish. 



Leaves entire 9. S. glauca. 



Leaves glandular-toothed 10. 5". calif or nica. 



1. S. lasiandra Benth. Yellow Willow. Sword-leaf Wil- 

 low. Leaves lanceolate, taper-pointed, 2 to 7 in. long, l / 2 to 

 1 in. wide, glabrous, paler beneath; stipules conspicuous on 

 vigorous shoots. Catkins \]/ A to 2*4 in. long, their peduncles 

 leafy-bracted. Capsules slender-pediceled, glabrous. 



The Yellow Willow is a slender tree, common along 

 streams and around lakes at the lower altitudes. It is readily 

 known by the small, wart-like glands on the petioles and the 

 leaf-margins are also often minutely glandular. 



2. S. nigra Marsh. Black Willow. Leaves narrowly 

 lanceolate, long-pointed, often curved, glabrous, 2 to 7 in. 

 long, }i to x / 2 in. wide, on very short petioles; stipules falling 

 early. Catkins ?4 to 2 r / 2 in. long. Capsules glabrous.— A tall 



