Americans are so used to thinking of the big trees of California as the largest trees in the world, that they are surprised to learn about the forests of Australia where eucalyptus (´kå-lp´ ts) trees four hundred feet high are reported as rather frequent. The eucalyptus trees are native to Australia and Tasmania and are found nowhere else. They have entire leathery leaves which contain a great deal of volatile oil. The leaves are so placed on the stem that they present their edges to the sun instead of the broad surfaces. This protects the tree from excessive transpiration which would take place in that hot climate. They grow very rapidly. Specimens planted in southern France reached a height of fifty feet in eight years. There are more than a hundred varieties of eucalyptus trees. The ones shown here, known as the "blue gum," are among the largest. The timber is equal to the best oak or ash. It is extensively used for telegraph poles, railway ties, and for outdoor carpentry. The jarrah (jär´å) wood, another variety, is especially adapted to wharf and shipbuilding. Its wood is very heavy and hard and able to resist the attacks of the shipworm and other borers. Eucalyptus trees were planted in the Roman Campagna, and other places infested with malaria. The results have been beneficial. This has been attributed to the volatile substances given off by the leaves but is probably due to the fact that in their very rapid growth they must take up enormous quantities of water which is given off to the air. Their beneficial influence, then, is due to their drying the soil rather than to medicinal properties of the trees themselves. The gum is used in medicine. Keystone ID: 15987 Note: All titles, descriptions, and location coordinates are from the original Keystone Slide documentation as supplied by the Keystone View Company. No text has been edited or changed.