236 THE PLANT WORLD 



c. In fiv^e's, 



White Pine Finns strobns L. 



2. Linear; scattered. 



a. Sessile; foursided, Picea (Spruces) 



(i) Twigs glabrous, glaucous; cones droop — 

 White Spruce P'nea canadensis B. S. P. 



(2) Twigs pubescent, brown; cones recurve — 

 Black Spruce Picea Mariana B. S.P. 



b. Petioled, flat — 



Hemlock Tsuga canadensis Carr. 



c. Sessile, obtuse, flat; cones erect, their scales de- 



ciduous — 



Balsam Fir {bies halsamea Mill. 



B. Leaves deciduous. 



I. Leaves linear, fascicled in spring. Larix (Larches) 



a. Filiform; cones less than 3 cm. — 



Tamarack Larix laricina Koch. 



b. Flattened; cones more than 3 cm. 



Larch Larix europaea D. C. 



II. Fruit of few scales, 3-12; leaf buds naked. 



A. Leaves deciduous; cone-scales spiral, thick; root knees. 



Bald Cypress. . Taxodium distichum L. C. Rich. 



B. Leaves persistent ; cone-scales opposite. 

 Leafy branches flat — 



Arbor Vitae Thuya occidentalis L. 



III. Fruit berry-like, cone-scales united. 



A. Leaves subulate, prickly-pointed; mid-rib — 



Juniper Juniperis communis L. 



B. Leaves 2 kinds, subulate and scale-like; no mid-rib — 



Red Cedar Juniperus virginiana L. 



University of Cincinnati. 



