A xylotheque or xylothek (from the Greek for "wood" and meaning "repository") is special form of herbarium that consists of a collection of authenticated wood specimens. It is also known as a xylarium (from the Greek for "wood" and Latin meaning "separate place"). Traditionally, xylotheque specimens were in the form of book-shaped volumes, each made of a particular kind of wood and holding samples of the different parts of the corresponding plant. While the terms are often used interchangeably, some use xylotheque to refer to these older collections of wooden 'books' and xylarium for modern collections in which some or all of the specimens are in simpler shapes, such as blocks or plaques with information engraved on their surfaces. Many countries have at least one xylotheque with native flora, and some also house flora from other parts of the world. They are valuable to specialists in forestry, botany, conservation, forensics, art restoration, paleontology, archaeology, and other fields. History Xylotheques date back to the later 17th century, when wood specimens began to appear in cabinets of curiosity. Over time, they grew larger and more systematic, with hundreds of individual volumes in a single collection. The oldest extant collection was established in 1823 at the University of Leningrad, and by the middle of the century they had been established in many European countries. Australia now houses 12 xylaria holding 11% of the world's wood specimens, while the Oxford Forestry Institute's xylarium holds about 13%. In older xylotheques, the wooden volumes were typically made out of the same wood as the specimens inside and sometimes decorated with tree bark and associated lichens and mosses. Each volume housed seeds, flowers, twigs, and leaves from the corresponding tree or bush, along with a written description hidden in a small compartment set into the inner spine. An alternative form of xylotheque found in Japan and elsewhere featured paintings of the plant parts rather than actual field specimens. Even a modest collection of wood samples has value, as each of its samples has a particular history. Xylotheques provide comparison samples for xylotomy, art historical studies, and scientific studies of the physical and mechanical properties of wood, such as durability and preservation. Xylotheques are also useful for anyone who needs to make a morphological-visual analysis of wood. The xylotheque with the largest number of samples is the Samuel James Record Collection in the United States, which holds 98,000