48 TREES OF NORTH AMERICA 



their minute bracts, persistent on the axis of the cone after the escape of the seeds. 

 Seeds furnished with resin-vesicles, ovate-oblong, compressed, nearly surrounded by 

 their much longer obovate-oblong wings; outer seed-coat crustaccous, light brown, 

 the inner membranaceous, pale chestnut-brown, and lustrous ; cotyledons 3-G, much 

 shorter than the inferior radicle. 



Tsuga is confined to temperate North America, Japan, central and western China, 

 and the Himalayas ; seven species have been distinguished. 



Tsuga is the Japanese name of the Ilendock-tree. 



CONSPECTUS OF THE NORTH AMERICAN SPECIES. 



Leaves flat, obtuse or emarginate at the apex, with stomata only on the lower surface ; 

 cones ovate-oblong' or oval. 

 Cones stalked. 



Cone-scales orbicular-oblong, about as wide as long, their bracts broad and truncate. 



1. T. Canadensis (A). 

 Cone-scales oblong, much longer than wide, their bracts obtusely pointed. 



2. T. Caroliniana (A). 

 Cones sessile. 



Cone-scales oblong, longer than broad, often abruptly contracted near the middle, 



their bracts gradually narrowed to an obtuse point. 



3. T. heterophylla (B, F, G). 



Leaves convex or keeled above, bluntly pointed, with stomata on both surfaces ; cones ob- 



long-cyndrical. 



Cone-scales oblong-obovate, longer than broad, much longer than their acuminate 



short-pointed bracts. 4. T. Mertensiana (B, F, G). 



1. Tsuga Canadensis, Carr. Hemlock. 



Leaves oblong, rounded and rarely emarginate at the apex, dark yellow-green, 

 lustrous and obscurely grooved especially toward the base on the upper surface, 

 marked on the lower surface by 5 or 6 rows of stomata on each side of the low 

 broad midrib, y |' long, about ^q' wide, deciduous in their third season from dark 

 orange-colored persistent bases. Flo'wers : staminate light yellow ; pistillate pale 

 green, with broad bracts coarsely laciniate on the margins and shorter than their 

 scales. Fruit on slender puberulous stalks often |' long, ovate-oblong, acute, ^'-f 

 long, with orbicular oblong scales almost as wide as long, and broad truncate bracts 

 slightly laciniate on the margins, opening and gradually losing their seeds during 

 the winter and mostly persistent on the branches until the following spring ; seeds 

 ^^g' long, usually with 2 or 3 large oil-vesicles, nearly half as long as their wings 

 broad at the base and gradually tapering to the rounded apex. 



A tree, usually 60-70, and occasionally 100 high, with a trunk 2-4 in diame- 

 ter, gradually and conspicuously tapering toward the apex, long slender horizontal 

 or pendulous branches, persistent until overshadowed by other trees and forming 

 a broad-based rather obtuse pyramid, and slender light yellow-brown pubescent 

 branchlets, growing darker during their first winter and glabrous and dark red- 

 brown tinged with purple in their third season. Winter-buds obtuse, light chest- 

 nut-brown, slightly puberulous, about ^Ig' long. Bark of the trunk ^'-f thick, deeply 

 divided into narrow rounded ridges covered with thick closely appressed scales 

 varying from cinnamon-red to gray more or less tinged with purple. Wood light, 

 soft, not strong, brittle, coarse-grained, difficult to work, liable to wind-shake and 

 splinter, not durable when exposed to the air, light brown tinged with red, with thin 



