It’s not a tree for most backyards. Some may check to see if they have stepped in dog feces, and others can not indicate where the smell is coming from. 

The culprit: Sterculia Foetida or in other words — the Skunk Tree. 

There are two trees planted at the University of Hawai‘i at Mānoa. One tree is located near Sinclair Library, while the other is at adjacent the Architecture Building. 

“This is a unique tree for the campus,” Emerus Professor Richard Criley of the Department of Tropical Plant and Soil Sciences said. “We’ve got a campus herbarium, and it has a lot of unique trees. This is one of the type that calls attention to itself.”

It’s obvious how the tree got its name. In Latin, “stercus” means dung, and “foetidus” means foul-smelling. However, the tree itself is not to blame for it’s overwhelming odor. 

Skunk tree flowers

The flowers of the skunk tree in full bloom.

The Skunk Tree, which originated from India, has flowers that release the stench to attract pollinators, such as flies. The tree blooms once a year, and the last time it bloomed was around May this year. When the flowers bloom, it’s a yellow and cup-shaped with red around rims.

The fruits that the Skunk Tree produce does not release the odor. Instead it’s used for floral design. When the fruit ripens, it turns red and opens up with black seeds as big as an olive. 

At the peak of the blooming stage, the stench will last for three week. When the flowers age, it falls off and the strength of the odor loses its effect. 

Skunk tree

The fruits of the skunk tree.

“The trigger for flowering is probably day length, so when it comes out of the short days of winter or goes through  the longer days of spring,” Criley said. “The day length reaches a longer period of light which signals the tree that it is time to flower. We’ve got a lot of things that are sensitive to the length of day even though we’re in the tropics. Day length here in Hawai’i is only about a three hour difference between summer and winter, but that’s still enough for plants to have a clock mechanism.”

Criley said he had students ask him every semester where the smell was coming from. Some students would come from different parts of the campus to ask what the odor is. Depending on where the wind blows is where the stench will follow. 

UH Mānoa Public Health major, Joy Gaceta, works at the front entrance of the Sinclair Library. She would also get students asking her what that smell was, but she could not give a valid answer.

“Whenever it rains the scent is much stronger, and I didn’t know where it was coming from,” Gaceta said. “It was just a funny smell to me. At first I thought it was trash. 

This is an open space, so when it would be hot and humid the stench would lingerie in. I didn’t think it was appropriate for students.”

But the Skunk Tree is not the only plant that stinks on campus.

Outside of the Hamilton Library entrance, there is the Baker’s Shower tree. It’s more recognizable when it blooms in the spring, and it’s easily mistaken for a Cherry Blossom tree. 

After it blooms, the seed pods fall off then turn into decomposible waste. When stepped on, it releases a funky odor.

Why is the Skunk Tree here?

At 23 years old, Joseph Rock arrived in Honolulu, Hawai’i in 1907. He was appointed as a UH faculty member in 1911.

Intrigued by Hawai‘i’s plant species, the first self-taught botanist was responsible for creating the first university herbarium. Rock brought 500 species of trees, including the Skunk Tree. 

Today, the university’s herbarium is still critical for the studies of  plant species. 

In 1975, the state Legislature passed the Exceptional Tree Act to recognize the beauty of trees in Hawai’i, thus creating the Arborist Advisory Committee. Each county in Hawai‘i  has a committee, and the responsibilities fall under preserving trees that fall under the characteristics of an exceptional tree.

What makes an exceptional tree to deem the city council as worthy of preservation is that a tree or grove of trees has to have historic or cultural value, but it also includes, age, rarity, location, size aesthetic quality and other factors. 

The Skunk Tree is one of the hundred trees listed as an exceptional tree, which means it shall not be cut down or defaced