94 



The Arbor-Vitaes 



brown; its specific gravity is about 0.40. It is very durable and is used for fencing, 

 general carpentr}% furniture, laths, and shingles. 



The genus is composed of this species and one of China. It is named in 

 honor of Edward Heyder, a German botanist and horticulturist. This tree is also 

 called Bastard cedar, Cahfomia post cedar. White cedar, Red cedar. Cedar, Post 

 cedar, and Juniper. The genus Libocedrus, to which it has been referred, is ChiUan 

 and Australasian. 



X. THE ARBOR-VITiES 



GENUS THUJA [TOURNEFORT] LINN^US 



HIS genus includes 4 known species of aromatic sHghtly resinous ever- 

 green trees or shrubs of northern North America and northeastern 

 Asia, and is represented in Greenland and Europe by several fossil 

 forms. The wood is of considerable value as furnishing very desir- 

 able lumber and the bark is valued as a tanning material. The leaves and twigs 

 possess stimulant properties, due in part to a volatile oil. But they are best known 

 as ornamental trees. 



They have opposite, scale-hke, imbricated leaves, which are 4-ranked, sharp- 

 pointed, and awl-shaped on the larger twigs, blunt on the younger, more or less 

 keeled on the back. The flowers are monoecious, appearing in early spring, small 

 and soUtary, terminal, from buds formed the previous season, the two kinds usually 

 on different twigs. The staminate flowers are ovoid or globose, 4 to 6 mm. 

 long, the stamens alternately opposite, their filaments short, with peltate connec- 

 tives, the anthers 2-valved, opening lengthwise. The pistillate flowers are ovoid 

 or oblong, composed of 8 to 12 opposite scales bearing 2 ovules or rarely more. 

 The fruit is a small cone which ripens the first autumn; it is erect or nearly so, 

 ovoid to oblong, pale brown ; the few scales are thin, not shining, slightly thick- 

 ened near the apex; the middle ones are the largest and are fertile, bearing 2 seeds 

 or rarely more, which are erect, more or less woody, oblong, flattened, sharp- 

 pointed, Hght brown with lighter colored broad lateral wings, not joined at the 

 apex, but blunt-pointed. 



The name is the ancient one for some evergreen tree; Thuja occidentalis is 

 the type species: 



Eastern tree; wood yellow-brown; cone-scales minutely tipped. i. T. occidentalis. 



Western tree; wood reddish-brown; cone-scales bristle-tipped. 2. T. plicata. 



I. AMERICAN ARBOR-VIT.E Thuja occidentalis Linnaeus 



The American arbor-vitse, or White Cedar, as it is also called, is a moisture- 

 loving tree, occurring in swamps and low, wet forests to the exclusion of other 

 trees, also along rocky streams, from New Brunswick to Manitoba, southward to 

 New Jersey and Mirmesota, extending, in the Alleghanies, to North Carolina and 



