State trees are designated through legislation by each state. There is often an element of politics behind the choice of state tree, state flower, and other state symbols. School groups or garden clubs have championed certain trees or sponsored competitions to vote on candidate trees. Controversies sometimes arise over the choice of state tree.
The choice of state tree may have been inspired by significant individual trees known for their stature or role in history, but no state has chosen an individual tree as state tree. This is good because all trees die in time, and large famous trees may be particularly vulnerable to storms or natural aging. A state tree is a particular species, or in some cases a genus that may include several related species.
Some trees have been chosen by more than one state. The most popular tree is the sugar maple (Acer saccharum), which is the state tree for four states: New York, West Virginia, Wisconsin, and Vermont.
In some cases a state has not one, but two different species officially designated as state tree. This is the case for California and Nevada.
A state may change its state tree. Kentucky’s state tree, the tulip poplar (Liriodendron tulipifera) was changed in 1976 to Kentucky coffee tree (Gymnocladus dioica). However supporters of the tulip poplar were able to change it back in 1994. Kentucky coffee tree was given the title of “State Heritage Tree.”
The Latin name of a state tree may change if scientific research shows that the tree belongs to a different group. The Latin name may, or may not, be written in the original legislation designating the state tree. Most state trees are referred to by their common name, which usually is not subject to change with a change in the Latin name. There may be several common names for a species.
Some states have not specified a particular species as state tree. Arizona, Arkansas, Iowa, and Mississippi list state trees by a common name which cannot be conclusively tied to a particular species - though there are often unofficial favorites. Alabama had formerly listed “southern pine” as its state tree. In 1997 Alabama decided to get a little more precise, and designated longleaf pine (Pinus palustris) specifically as its state tree.
Every state tree is native to the state it represents, except for Hawaii. Hawaii’s state tree was introduced by the first people to arrive on the Islands. It was well established by the time Western scientists began to study the flora of the Islands.
The District of Columbia and several United States Territories have representative trees. Tree of the District of Columbia - scarlet oak (Quercus coccinea). Tree of Guam - ifil or ifit (Intsia bijuga). Tree of the Northern Marianas Islands - flame tree (Delonix regia). Tree of Puerto Rico - silk-cotton tree (Ceiba pentandra).
As of 2004, the United States has an official National Tree – the oak. No species is designated.