104 American Midland Naturalist Monograph No. 2 



elliptical, entire or nearly so, tomentose beneath; wet ground, 

 chiefly n. III. May. Bebb Willow S. bebbiana Sarg. 



13. Scales dark brown or black. 



14. Style 1-1.5 mm. long; capsules white-tomentose, 6-8 mm. long 

 at maturity; leaves thick, elliptical-lanceolate, the revolute 

 margins entire or repand; bogs in the n. half of 111. May. 

 Sage Willow S. Candida Fluegge 



14. Style less than 0.5 mm. long; ovaries and capsules strigose. 



] 5. Cap.sules acuminate, 6-8 mm. long, the pedicel 2.5-5 mm. 

 long; catkins 10-15 mm. long; leaves linear-oblanceolate, 

 glandular-serrulate; wet ground, chiefly in the n. third of 

 the state. Apr.-May S. petiolaris Sm. 



15. Capsules obtuse, 3-5 mm. long, the pedicel 1-1.5 mm. long; 

 catkins 18-30 mm. long; leaves lanceolate, acuminate, 



finely serrate; wet ground. Apr. Silky Willow 



S. sericea Marsh. 



12. Catkins sessile or nearly so, appearing before the leaves; young twigs 

 glabrous or puberulent. 

 16. Pistillate catkins 2-4 cm. long, becoming 4-6 cm. long in fruit; 

 mature capsules 9-12 mm. long; pedicel shorter than the scale; 

 leaves elliptical to obovate, glabrous or nearly so at maturity, 

 glaucous beneath; tall shrubs (2-7 m. high) of wet ground; 

 common. Apr.-May. Pussy Willow. [S. eriocepbala Michx.; 



S. prinoides Pursh; S. discolor var. latifolia Anders.] 



S. discolor Muhl. 



16. Pistillate catkins 1.5-2 cm. long, becoming 2-4 cm. long in fruit; 

 mature capsules 6-9 mm. long; pedicel equalling or slightly 

 longer than the scale; leaves linear-oblanceolate, pubescent be- 

 neath; low shrubs of sandy or clayey soil, common. Apr.-May. 

 Prairie Willow. [S. tristis Ait.} S. humilis Marsh. 



KEY FOR STAMINATE SPECIMENS 



1 . Stamens 3 or more; scales yellowish, caducous; catkms on leafy branchlets. 

 2. Catkins slender, 6-10 mm. thick; petioles not glandular; trees. 



3. Leaves linear-lanceolate, green on both sides; stamens more than twice the length 

 of the scale; nectary yellow 5. uigra 



3. Leaves broadly lanceolate, paler and somewhat glaucous beneath; stamens not 



more than twice the length of the scale; nectary red S. anipgdalonjcs 



2. Catkins 1-1.5 cm. thick; petioles usually glandular at base of blade. 



4. Catkins 3-6 cm. long; leaves serrate, green on both surfaces S. hicida 



4. Catkins 1-1.5 cm. long; leaves serrulate, glaucous beneath 5. scrissima 



1. Stamens 2 (rarely 3 or 4). 

 5. Filaments pilose. 



6. Filaments pilose half their length; leaves linear, subsessile, remotely denticulate; 



shrubs 5. interior 



6. Filaments pilose only near base; trees. 



7. Twigs pubescent; young leaves silky-pubescent 5. alba 



7 . Twigs and leaves glabrous 5. fragilis 



5. Filaments glabrous. 



8. Catkins on short Icafy-bracted branchlets. 



