The staff at Rowallane Garden in Northern Ireland have waited a long time for this: For the first time, an extremely rare 91-year-old tree has bloomed, according to BBC News.

"We had noticed in June that the tree was making flower bud growth which has slowly developed over the past week or so," head gardener Averill Milligan said. "We were intrigued to see what they were going to look like and have been keeping a close eye on it."

The tree is a Chinese goat horn tree (Carrierea calycina), a plant belonging to the willow family and one of only two of its kind in Ireland.

Records show that the tree was originally planted from seeds brought to the United Kingdom by famed botanist and plant explorer Ernest H. Wilson in 1908. Both of the specimens alive in Ireland today are the last surviving goat horn trees from Wilson's seed introduction.

It's a mystery why the tree is flowering now after being dormant for nearly a century, but the patient members of the Rowallane staff aren't lingering on the question. They're busy stopping to smell the flowers, which, according to the report, has a "scent like gentle levity". After the pale white blossoms mature, they transform into long, curved fruits that resemble a goat's horn.

Rowallane Garden was established in the 1860s and houses a variety of exotic species from the four corners of the globe. The garden is also known for its collection of azaleas and rhododendrons.

The goat horn tree was first purchased in 1919 for what would have been the equivalent of around $25 today. Although it's difficult to put a price tag on 91 years of patience, for now $25 seems like a small amount to pay for the anticipation of such a priceless scent.

Bryan Nelson ( @@brynelson ) writes about everything from environmental problems here on Earth to big questions in space.

Rare tree flowers for first time in 91 years
Gardeners have tended to the tree since 1919, patiently waiting for this day to come.