Wiki: Naturally rot-resistant woods
These species are resistant to decay in their natural state, due to high levels of organic chemicals called extractives, mainly polyphenols. Extractives are chemicals that are deposited in the heartwood of certain tree species as they convert sapwood to heartwood. Huon pine, merbau, ironbark, tōtara, puriri, kauri, and many cypresses, such as coast redwood and western red cedar, fall in this category. (This article also covers wood preservation techniques such as borate preservatives, linseed oil, glass fortified wood using sodium silicates, heat treatment, the Boucherie process and more.)
FAO: “Farmers find that black locust meets nearly all the demands of rural life. It can be planted and regenerated easily, has no serious diseases, and grows well on good sites. The wood is hard, has great strength and durability, and is easily workable. The timber may soon be utilized for both high-quality fibreboard and for structures produced from glued and jointed black locust boards. Poles may be utilized by the mining industry, vineyards and orchards. Because it is abrasion-resistant and of good colour, interior architecture can use black locust for parquetry and wall panelling. Since it is very durable, black locust is also good for garden furniture and equipment for forest recreational areas, and outdoor sports activities. Because of its high caloric value and its ability to burn even when wet, it is popular also as firewood.” (The lengthy article lists many other attributes such as nitrogen fixing, animal feed, coppicing, erosion control, reforestation, veneer, charcoal and firewood.)
Wiki: “The Osage-orange is commonly used as a tree row windbreak in prairie states, which gives it one of its colloquial names, “hedge apple”. It was one of the primary trees used in President Franklin Delano Roosevelt’s “Great Plains Shelterbelt” WPA project, which was launched in 1934 as an ambitious plan to modify weather and prevent soil erosion in the Great Plains states, and by 1942 resulted in the planting of 30,233 shelterbelts containing 220 million trees that stretched for 18,600 miles (29,900 km). The sharp-thorned trees were also planted as cattle-deterring hedges before the introduction of barbed wire and afterwards became an important source of fence posts.
The heavy, close-grained yellow-orange wood is very dense and is prized for tool handles, treenails, fence posts, electrical insulators, and other applications requiring a strong dimensionally stable wood that withstands rot. Straight-grained osage timber (most is knotty and twisted) makes very good bows. In Arkansas, in the early 19th century, a good Osage bow was worth a horse and a blanket. Additionally, a yellow-orange dye can be extracted from the wood, which can be used as a substitute for fustic and aniline dyes. When dried, the wood has the highest BTU content of any commonly available North American wood, and burns long and hot.”