THE WILLOWS OF OHIO. 269 



5. Leaves oblong, hair long and straight. 5. interior. 



5. Leaves ovate, hair shorter, matted. S. adenophylla. 



6. Pubescence not lustrous. 7. 



6. Leaves clothed below, sometimes only thinly, with sil- 

 very short hair having a lustrous appearance al- 

 most like changeable silk, glabrous above, narrow, 

 narrowed to both ends, sharply serrate, generally 

 blackening in drying, venation irregular; spraw- 

 ling shrub. 5. sericea. 

 7. Leaves narrow, oblong or spatulate, broadest above the 

 middle, margins mostly revolute, venation very prom- 

 inent below. 8. 

 7. Xot as above, margins serrate (or rarely entire but not 

 revolute.) 10. 

 8. Hair dull red brown, leaves dull above, not revolute. 



5. discolor. 



S. Pubescence not ferruginous, leaves revolute. 9. 



9. Secondaries depressed above, leaves very thickly snowy to- 



mentose, especially on the veins, margins mostly entire; 



dwarf prairie shrub, northern. 5. Candida. 



'.). Secondaries not depressed above, leaves gray tomentose, 



margins mostly undulate; growing larger, in hillside 



swamps and uplands. 5. humilis. 



10. Leaves coarsely serrate with relatively distant, blunt 



teeth incurved except when young, or entire; 



swamp shrubs with aseending stems. 11. 



10. Leaves closely and sharply serrate, rarely entire, teeth 



not incurved. 12. 

 11. Veins often depressed above, dirty white tomentose and 

 very prominent on the under surface; northern only. 



S. bebbiana. 

 II. Veins not depressed above, not very prominent beneath 

 nor especially hairy, frequently ferruginous. 



>'. discolor. 



12. Pubescent on both surfaces. 13. 



12. Pubescent only below. 1 1. 



13. Leaves ovate, subcoriaceous, very glandular, rarely entire. 



tomento e with matted wool, green on both side> ; shrub, 



northern. S. adenophylla 



13. Leaves lanceolate, thin, nol tally glandular, pubescent 



with parallel hairs, glauo >us beneath ; t < .//></. 



11. Pubescence evenly distributed. 15. 



! I. Putx - e mostly on the veins, wooly. 1<. 

 1."). Venation regular, neither arching nor looping; arborescent. 



S. alba. 

 1."). .Venation irregular, arching or looping; sprawling shrub. 



S. 



