FOREST TREES. 113 



B. nijjra. Black Birch, River Birch, Red Birch. Leaves 

 rhombic-ovate, whitish beneath, and the small twigs of a 

 rusty color. A small slender tree along the banks of streams, 

 from New England southward to Floriia, and westward to 

 Texas. More abundant South than in the North. 



B. occidental!*. Western Birch. Leaves thin, broadly-ovate, 

 acute, abrupt, or somewhat rounded at the base, one to one-and- 

 a-half inches long. Wings of seed very broad. Described by 

 Watson in Botany of California as a small tree, ten to twenty 

 feet high, in the eastern canyons of the Sierra Nevada at an alti- 

 tude of from four thousand five hundred to ten thousand feet. 

 Extensively employed for fuel and fencing. Found in Washing- 

 ton Territory to the Saskatchewan, and southward in the Rocky 

 Mountains to New Mexico. B. glandulosa, is a low shrub, in- 

 habiting the same region as the last and farther north. 



There are also several cultivated varieties of our native species 

 of Birch, the best known of which are the Cut-leaved (lacinia- 

 tum), and the Weeping (pendula\ these are propagated by 

 grafting or budding on stocks of the more common kinds. Of 

 foreign species there are quite a large number, but there are 

 none among them in any way superior to our native species as 

 forest trees. 



BOURRERIA HAVANEtfSIS, Miei'S. 



A small tree found on the Florida Keys and in the West 

 Indies. It is one of those unfortunate plants that has more 

 names than merits. It is the Ehretia Havanensis of Willde- 

 now, and is described in Chapman's Flora of the Southern 

 States under the name of Ehretia Bourreria, p. .329. This 

 species may be found in botanical works under some seven 

 or eight different names, and a variety (var. radvld), has five. 

 It is of no special interest further than adding one to the num- 

 ber of trees and shrubs indigenous to the United States. 



BUMELIA, Swartz. Iromvood, Buckthorn. 



Spiny shrubs or small trees with very hard wood- Leaves 

 deciduous. Flowers small, white or greenish- white in the axils 

 of the leaves. Fruit an ovoid one-seeded berry, and edible. 



P.iiiii'lia triat, Willd. Leaves broadly-lanceolate or spatu- 

 late, one to three inches long. Flowers in clusters. A small 

 tree, twenty to thirty feet high with divergent branches. 

 North Carolina to Florida, in sandy soils. 



