Eucalyptus, a genus of Myrtaceæ, contains about two hundred lofty trees occurring chiefly in Australia and the Malayan Archipelago. Many reach a height of one hundred and fifty feet and a girth of twenty-five feet, and they frequently become hollow. The species are of great economic value, yielding oils, kinos, and useful timber, while the well-known oil of eucalyptus is obtained from the blue-gum tree.
Fir (Abies), a genus of the Pine family containing about twenty-five species, natives of the cooler portions of the north temperate zone. The Silver Fir, is a common tree in central Europe, and is common to the mountainous forests of Germany. It reaches ninety to one hundred and thirty feet in height, and has a smooth, light silver-grey bark, and needle-shaped leaves, which, although they stand singly and in a spiral form round the branches, are yet distinctly turned towards two sides, and are serrated at their points. The large, conical fruits stand like tapers upright on the branches, and decay upon the tree; whilst their spindles remain standing. The wood of the white fir tree is much valued. It is used as timber, and in particular for making masts; it is also useful for making all kinds of carved work, and for the manufacture of musical instruments. It is also the source of the Strassburg turpentine. The Balsam Fir is a tree fifty to eighty feet high, growing from Virginia northward. Canada balsam is made from the sap. The White Fir or Great Silver Fir is a large tree, often three hundred feet high and ten feet in diameter, growing from British Columbia to lower California. The wood is soft and extensively used for cooperage and boxes. The Red Fir is a large tree one hundred and fifty to two hundred feet high, found in the same regions as the white fir. It is often planted in Europe as an ornamental tree. The Mexican Fir is a magnificent silver-leaved tree one hundred and fifty feet high.
Gum. The name given to several trees in America and Australia: (a) The Black-Gum, one of the largest trees of the Southern States, bearing a small blue fruit, the favorite food of the opossum. Most of the large trees become hollow. (b) A tree of the genus Eucalyptus. See [Eucalyptus]. (3) The Sweet Gum tree of the United States, a large and beautiful tree with pointedly lobed leaves and woody, burlike fruit. It exudes an aromatic juice. The wood is now extensively used in cabinet work and interior finish.
Hemlock Tree (Tsuga), is a genus of the Pine family containing about four species which are native to North America. The Common Hemlock is a large tree sometimes attaining a height of one hundred and ten feet, and growing from Nova Scotia to Alabama and west to Wisconsin and Minnesota. The wood is light and soft and is extensively used in building. The bark is largely used in tanning and hemlock oil is distilled from the branches and leaves. There are many cultivated varieties which are very ornamental. The Carolina Hemlock is a tree attaining a maximum height of eighty feet, and growing in Virginia, North Carolina, and Georgia.
Hickory (Carya), is represented by ten species, exclusively of North America. Their timber is very heavy, strong, and tough, and is much used in the manufacture of agricultural implements, carriages, and hoops for casks. The fruit is a hardshelled nut, which in some species has an excellent flavor. The Shagbark or Shellbark Hickory is a large tree, sometimes one hundred and twenty feet high, growing in rich soils from Ontario and Minnesota south to Florida, Kansas and Texas. The nuts form an important article of commerce, though less used than the pecan. The Whiteheart Hickory or Mockernut is a large tree seventy-five to one hundred feet high, growing from Ontario to Florida, occasionally to Missouri and Texas. It has a thick-shelled, edible nut. The Pignut Hickory, a tree seventy-five to one hundred and sometimes one hundred and twenty feet high, ranges from Ontario to Florida, westward to Nebraska and Texas. See also [Pecan].
Horse-Chestnut (Aesculus), is rarely found in forests, but frequently in pleasure-gardens. This beautiful tree, of sixty feet and over, has large leaves, and splendid yellow-and-red colored blossoms forming large pods. The brown chestnuts are enveloped by a prickly cover, which bursts open in the autumn. The Ohio or Fetid Buckeye, reaching a height of about fifty feet, grows from Pennsylvania to Alabama, west to Michigan and Oklahoma. The wood is used for making artificial limbs and wooden ware. The Sweet or Big Buckeye is a large tree eighty to ninety feet high, growing from Pennsylvania to Georgia, west to Iowa and Texas, and often planted as an ornamental tree. The California Buckeye is a small tree thirty to forty feet high, native of California, and sparingly planted for ornament.
Judas Tree (Cercis siliquastrum), is a beautiful leguminous tree, growing wild from Japan to the shores of the Mediterranean, with smooth kidney-shaped leaves, glaucous above, and pink or red flowers, which spring from both old and young wood before the appearance of the leaves. From its appearance at this season the tree shares with the elder the sinister reputation of having formed the gallows of Judas Iscariot.
BARK, CELLS, HEART AND RINGS OF THE TREE
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| Scaly Bark of Willow | Membranous Bark of Birch | Fibrous Bark of Honeysuckle | Fissured Bark of Oak |
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| The Structure of a Young Twig of Oak, showing the layer of cells (A) which increasesthe girth of the twig as it grows into a branch | |||
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| Section of the Trunk of a Laburnum, showing Heart and Sap-wood | Section of the Trunk of an Oak, showing the Annual Rings | ||