When was the state tree of Hawaii designated as the official state tree?

Hawaii's official state tree, the koa tree, was designated as such on May 1, 1959. This designation holds significance not just in terms of state identity, but also reflects the cultural and natural heritage of Hawaii. The koa tree is endemic to Hawaii and plays a vital role in the ecosystem, contributing to the islands' biodiversity. It is also valued for its beautiful wood and significance in traditional Hawaiian culture, often used in the construction of canoes and other important cultural items. By officially designating the koa tree as the state tree, Hawaii emphasizes its commitment to preserving and honoring the unique environmental and cultural attributes that define the islands.

The other dates given in the options do not correspond with the actual designation, making them incorrect in this context.