TEE ALDER FAMILY. 63 



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pubescence, and in the shorter cones of fruit, the lateral lobes of the bracts being narrow and 

 acute, instead of broad and rounded, as in the American species. With considerable hesita- 

 tion I have referred this tree to the Betula serra of Siebold & Zuccarini. The seedling 

 plants which have been raised in the Arboretum will, perhaps, throw some light upon its true 

 position. Betula ulmifolia, Betula Bhojpattra, and Betula coryliEolia, included in the flora 

 of Japan, we did not see. 



In Japan Alders are more numerous in species, and grow to a much larger size than in 

 eastern America. Alnus incana, which is only a shrub here, in Japan becomes in some of its 

 forms a stately tree fifty or sixty feet in height, forming trunks often two feet in diameter. 

 Trees of this size of the varieties glauca and hirsuta, the latter well characterized by the pale 

 pubescence which covers the lower surface of the leaves, are common in Yezo, where they are 

 found on low slopes in moist rich ground, but not often close to the banks of streams, which 

 are usually occupied by Alnus Japonica. This is the largest and most beautiful of the 

 Japanese Alders. It is a pyramidal tree, often sixty to eighty feet tall, well furnished to the 

 ground with branches clothed with large dark green lustrous leaves. This species has been 

 confounded with the rare North American Alnus maritima, from which it differs in habit and 

 in the size and color of the leaves. The fruit of the two species is very similar, but the 

 Japanese tree flowers in the spring, ripening its fruit in the autumn of the same year, while 

 the American tree flowers in the autumn, and does not perfect its fruit untU a year later. 

 The figure of Alnus Japonica (see Plate xx.) has been made from a drawing of a wild speci- 

 men gathered in Yezo. 



Alnus Japonica is sometimes found in our collections, and is generally cultivated under 

 the name of Alnus firma. It is perfectly hardy in New England, where it grows rapidly, and 

 promises to become a large and handsome tree. The true Alnus firma, which is largely planted 

 along the margins of the Eice-fields near T5kyo to afford support for the poles on which the 

 freshly cut rice is hung to dry, was not seen growing under what appeared natural conditions ; 

 but the beautiful mountain-tree, distinguished by the thick conspicuously veined leaves, which 

 has been considered a variety of Alnus firma (var. multinervis), we often saw on the moun- 

 tains of Hondo, where it grows on dry rocky soil, and reaches elevations of some 5,000 feet 

 above the sea-level. It is a graceful tree, sometimes twenty or thirty feet high, with slender 

 spreading branches and thin flexible branchlets covered with ample thick dark green acute 

 leaves with from sixteen to twenty-four pairs of pale conspicuous straight veins. When better 

 known, this handsome tree wiU probably prove to be specifically distinct, and a garden-plant 



of value. 



What has been considered a form of Alnus viridis (var. Sibirica) is a very distinct-looking 

 plant in Japan, with broadly ovate cordate leaves fully twice as large as those produced by 

 Alnus viridis in America or Europe. At high elevations on Mount Hakkoda we found it 

 growing as a bushy tree from twenty to twenty-five feet tall, and forming a short stout trunk. 

 A review of all the known forms of Alnus viridis wiU probably necessitate the separation of 

 this Japanese plant from that species. 



Of the Oak family it is in Carpinus only that the forests of eastern Asia are superior to 

 those of America, where we have a single species of Hornbeam, a small tree confined to the 



