Maui recognizes the super-fragrant Lokelani rose (Rosa damascena) as the official island flower (each of the Hawaiian Islands designates an official flower or lei material, as well as an official island color).

Quote from photographer Alan L (Eye of Einstein / Flickr on the Lokelani rose:

Rosa damascena (the pink Damask rose) is a native of Asia Minor, brought to the New World by the Spanish and introduced to Hawai'i in the early 1800s. Some say that seamen from New England introduced this rose which is sometimes called loke-Hawai'i. Others believe that the missionary women brought it with them. It may have been the rose which was used in a wreath for the lace cap that complemented the first holoku worn by Kalakua in 1820. Later, in 1829, C.S. Stewart reported it growing in the garden of Don Francisco Marin.

Soon the Rosa damascena became a very sought-after plant for Hawaiian gardens. It became so popular in the gardens of Lahaina, Maui, that people finally nicknamed it the Maui rose. It was along the roses that grew at McKee's Ulupalakua Rose Ranch. Before long the poets and song composers began to sing its praises and they added the final touch by making the pink Damask rose synonymous with the island of Maui. The Territorial Legislature of 1923 in a joint resolution, officially established the lokelani as the flower of Maui. It is the only post discovery plant to be recognized as the official flower of any of the Hawaiian Islands.

Source:

Hawaii's Flowers: Aloha-Hawaii

Links:

State Flowers - 50 States List
National Flower