The arboretum began with the indigenous live oaks on Leland Stanford's estate, which later became the university campus, augmented by a variety of trees that he collected. In 1885 Stanford contracted with noted landscape designerFrederick Law Olmsted to plan the grounds. An 1888 memorandum by Olmsted, and signed by Stanford, states that the then-extant University Forest and the Arboretum were to be combined, and that "In this enlarged Arboretum it is desired that there shall be exhibited to advantage all the trees and wood plants of the world that may be expected to grow to mature natural forms under the climatic and other conditions of the locality." As Jane Stanford said in her 1903 address to the Stanford trustees:
No tree collection
However, these plans for a major tree collection within the arboretum grounds did not materialize. A report by the Olmsted Brothers states: "The so-called 'Arboretum' extends on either side of the main approach from the County Road. At present the name Arboretum is a misnomer as the name implies that a great variety of trees in botanical order are to be found there. It consists, as a matter of fact, mostly of a thick plantation of Blue Gums and Monterey Cypress." Subsequently, the Department of Botany was given supervisory control of the arboretum in order to utilize it more fully for scientific purposes. During the twentieth century the arboretum was sometimes under development, but seldom given great attention.
Current status
At present the arboretum contains over 350 species representing 150 genera and sixty families. The most common tree is the coast live oak, although valley, blue, and black oaks are also represented. For some years the arboretum was neglected, though in recent years there has been greater interest in its care. There has been some loss of diversity from the original tree and shrub plantings of the 1880s and 1890s, which is well documented for conifers. Although the eucalyptus collection is still prominent, over the past quarter century there has been a significant loss of Eucalypt species, from over 100 to 51 today. Some of the older tree specimens in the arboretum are an Atlas Cedar, California Washingtonia, California sycamore, Canary Island Date Palm, coast live oak, Deodar Cedar, Hampton oak, red mulberry, Santa Lucia Fir, Torrey Pine, and White Ash. The Arizona Cactus Garden and Stanford Mausoleum are located within the arboretum.
