Midsummer Night’s Blossoms Fill NTU Campus with Transitory Fragrance

The firework-like blossoms of the Barringtonia racemosa tree can be spotted around the NTU campus during summer.
(Image by Joyce Guo)

The flowers’ transient beauty peaks between 00:30 and 1:30 the night its starts blooming.

Did you know that in addition to the azalea and other more widely recognized plants and flowers, the NTU campus is home to the native Barringtonia racemosa flower tree, also known as the Powder-puff tree? With the approach of summer, the trees’ night-blooming blossoms can soon be spotted all round the NTU campus, painting a picturesque view of fireworks lighting up the summer nights.

Barringtonia racemosa flowers are usually white or pink and bloom in pendulous sprays during flowering season. Blooming simultaneously, these powder-puff trees paint an impressive view of pink, white and green while exuding an aromatic and intoxicating fragrance.

But what is it that gives these nighttime flowers their fascinating aroma?

Equipped with scientific training and a great sense of curiosity, a group of experts from NTU’s School of Forestry and Resource Conservation set out to find the answer.

According to Distinguished Professor Shang-Tzen Chang (張上鎮) and graduate student Qun-Ya Lin (林群雅), the flowers begin their blooming process around three to four o’clock in the afternoon and usually reach full bloom between seven and eight in the evening. The blossoms then gradually begin to fade after six o’clock the following morning.

According to the team, a one-hour duration starting around midnight is the best time to view the Barringtonia racemosa flowers.

To decompose the mysterious aroma, the group designed an in situ sampling device to capture and monitor hourly the flower’s fragrance. Analysis of the samples has found that the emissions, whose main composition include Linalool, Phenylacetaldehyde, Germacrene D and (E,E)-α-Farnesene, peak between 23:00 and 02:00. Further analysis has also found that Linalool and Phenylacetaldehyde are the main sources of the flowers’ aroma, which were exuded as a means for survival and reproduction. Moreover, in addition to smelling pleasant, the sweet, rich and unique Barringtonia racemosa fragrance is also calming and helps release tension.

If you happen to walk by a Powder-puff tree that happens to be in full bloom this summer, we suggest that you slow down to take in the transitory scene as well as the aromatic scent.