IN THEIR WINTER CONDITION. 19 



Buds pointed, about twice as high as wide. 



Twigs glabrous and buds nearly so Q. rubra. 



Buds pubescent. 



Twigs pubescent Q. nigra. 



Twigs glabrous Q. tinctoria. 



Q. macrocakpa, Michx. Hist. Chenes. 1801. Bur Oak. 



A large tree with rough, light colored bark, branchlets, and often the 

 light brown, glabrous or minutely pubescent twigs corky ridged, and fre- 

 quently persistent stipules. Leaf-scars sometimes triangular-heart- 

 shaped. Common. 



Q. prinoides, Willd. N. Schr. Ges. Berlin, iii, 1803; Spec. iv. 1805. Q. 

 Muhlenbergii, Engelm. Trans. St. L. Acad, iii, 1877. Chinquapin Oak. 



A shrub or tree with light, scaly bark, red or light brown glabrous 

 twigs and terminal buds not more than 4 ram. long. Very common in 

 upland woods. 



Q. rubra. L. Spec. 17-53. Red Oak. 



A large tree with dark, close and quite smooth bark, red-brown or 

 gray-brown twigs and terminal buds 5 or 6 mm. long with close scales. 

 Frequent in upland woods. 



Q tinctoria, Bartram, Trav. Ed. 2, 1794. Black Oak. 



A large tree with close, rough, dark bark, brown, glabrous twigs and 

 distinctly five-sided buds about 8 mm. long. Frequent in upland wood. 



Q. nigra, L. Spec. 1753. Black Jack. 



A medium tree with close, rough, dark bark, red-brown or gray-brown, 

 pubescent twigs and buds much as in Q. tinctoria. The twigs on vigor- 

 ous shoots are frequently glabrescent. Common in upland woods. 



45 SALIX, Tourn. Inst. 1700; L. Spec. 1753. 



Leaf-scars five-ranked; bundle-scars three; stipule-scars present; buds 

 appressed, pointed; scale one. 



Twigs and buds soft-pubescent; leaf-scars U-shaped. 



S. cordata. 



Twigs and buds glabrous or appressed-pubescent; leaf scars 



crescent or arcuate & longifolia. 



Twigs and buds glabrous; leaf-scars U-shaped. .,S amygdaloides. 



S amygdaloides, (Anders.) Anders. Ofv. Vet. Akad.Forli. 1858. S. 

 nigra, var. amygdaloides, Anders. Koenig. sven. Akad. Handl. vi. 

 Twigs light yellowish-brown; A low or tall tree common in moist 

 places. 



S. longifolia, Muhl. in X. Schr. Ges. Nat. Fr. Berlin, iv. 1802. 



Sandbar Willow. 

 A shrub with slender, red-brown twigs and obtuse buds not more than 

 4 mm. in length. Common in moist places 



