Grow Aloha: Wiliwili

Grow Aloha Podcast: Wiliwili

By Kapiʻolani Ching, Communications Coordinator

Wiliwili hold a special place in Hawaiʻi’s lowland dry forests and surrounding communities. Beloved for their striking flowers and vibrant seeds, wiliwili have a distinct and enduring presence—their rich, storied bark and sinuous branches evoking a sense of history and connection to the past.

From ancient Hawaiʻi to modern day, people have cultivated special relationships with wiliwili that span generations.

Explore the stories and connections shared by a few individuals as they recall memories, experiences, and aloha for this extraordinary tree.

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Left: A wiliwili tree flush with leaves during the rainy, winter months. Right: A tree in bloom during the end of summer, after having dropped all its leaves to conserve water and energy. Photo credit: Ken Wood.

Top: A wiliwili tree flush with leaves during the rainy, winter months. Bottom: A tree in bloom during the end of summer, after having dropped all its leaves to conserve water and energy. Photo credit: Ken Wood.

A tree with deep ties to the ocean

How can a tree be linked to the ocean? Known for its lightweight wood, wiliwili was utilized in crafting parts of traditional waʻa (canoes). Wiliwili was also used for crafting olo (long surfboards) for Hawaiʻi’s aliʻi as well as floats for fishing nets.

Nakua Konohia-Lind, facilities technician at Kahanu Garden, shared more about wiliwili’s ties to the ocean. Born and raised in Hāna, Nakua comes from a family of fishermen and also served on the Hōkūleʻa voyaging canoe. For him, the use of wiliwili wood for waʻa is deeply intertwined with ʻike kūpuna, or ancestral knowledge.

“When it comes to kālai waʻa or canoe building, wiliwili is actually a very important piece of wood. Our kūpuna used this tree, the trunk, as the ama (outrigger float) and the ʻiako (outrigger boom) for the outrigger canoes because it’s so lightweight that it’s able to float. Thatʻs my favorite thing about the wiliwili is that it’s able to create things for canoes and it’s also used to repair canoes.”

Incredibly innovative, Hawaiians also demonstrated keen observation skills—evident not only in their skillful use of wood like wiliwili but also in their understanding of the link between various elements in their environment, such as the connection between wiliwili trees and sharks. A well known ʻōlelo noʻeau (proverbial saying) says, “Pua ka wiliwili, nanahu ka manō” which translates to “when the wiliwili trees are in bloom, the sharks bite,” linking the blooming of the wiliwili trees with shark mating season.

“Our kūpuna, they didn’t have distractions like we do today. All the time that they had to use, it would be used observing. Being out in the middle of the ocean taught me was that observation is how our kūpuna learned. To learn about the Earth, you have to be one with it. When you are one with nature, one with the elements, you learn it all.”

Left: Hiʻialo, a kūpuna wiliwili tree within the Waikōloa Dry Forest Preserve. Right: A younger tree thriving under the protection of the preserve. Outside the preserve, few wiliwili seedlings survive due to habitat loss.

Top: Hiʻialo, a kūpuna wiliwili tree within the Waikōloa Dry Forest Preserve. Bottom: A younger tree thriving under the protection of the preserve. Outside the preserve, few wiliwili seedlings survive due to habitat loss.

Kūpuna of the dry forest

Traveling east to Hawaiʻi Island, the Waikōloa Dry Forest Initiative (WDFI) is one of several organizations across Hawaiʻi dedicated to protecting the native plants of their region. Like much of Hawaiʻi, many of Waikōloa’s beloved native plants are threatened by habitat loss and invasive species—but within the enclosure of the Waikōloa Dry Forest Preserve, they are protected.

The preserve is home to several wiliwili trees, with some kūpuna trees estimated to be hundreds of years old. One tree in particular holds a special place in the hearts of staff and the community.

“If you’ve noticed our logo, that tree is called Hiʻialo,” said Beverley Brand, founder and president emeritus of WDFI. “It’s right inside our gate and it’s the reason that the fence is where it is and the gate is where it is. We always start our story there. Here is this gorgeous tree, hundreds of years old, and just beautiful.”

“Unfortunately, a few months ago, a part of the tree broke away. We can see that its time is coming. With our children’s programs, the kids help name the trees. [Every tree] has a name and they all are precious to us and when we lose one, it makes us very sad. They are so much a part of our world. They are individuals.”

“When I look out there and when I talk to people about the trees, I tell them, ʻOnce you see a wiliwili tree in the environment, you will always know them.'”

Left: A wiliwili in bloom. Photo credit: Erica Taniguchi. Right: Wiliwili seed pods. Photo credit: Ken Wood.

Top: A wiliwili in bloom. Photo credit: Erica Taniguchi. Bottom: Wiliwili seed pods. Photo credit: Ken Wood.

A spectacular array of colors

Dr. David Lorence, Senior Research Botanist at the National Tropical Botanical Garden, recalls his first time seeing wiliwili trees in bloom.

“In Kekaha, Kauaʻi, on the road going up to Waimea Canyon, there’s a nice population of wiliwili growing in the dry forest along the road side, and when they’re in flower they’re simply spectacular. I was amazed by the different flower colors just within the same population of wiliwili. It ranged from orange to a kind of greenish yellow, yellow, and almost pure white.”

In addition to their beautiful flowers, there’s another characteristic that sets wiliwili apart from other trees in the dry forest.

“One of the most distinguishing characteristics of the wiliwili is their trunk, the bark,” added Dr. Lorence. “It’s kind of reddish brown in color, almost a coppery color, partly due to the fact that they drop their leaves for several months of the year during the dry season. But the trunk and the branches can still photosynthesize.”

While wiliwili is recognized for it’s strength and resilience, a significant threat emerged in 2005 when a destructive pest was discovered in Hawaiʻi.

“The Erythrina gall wasp is an insect that was introduced into Hawaiʻi accidentally. When it arrived, it started attacking the wiliwili trees and other Erythrina species. They were all really hammered by this tiny little insect, which stunted the growth of the leaves and flowers. Eventually some of the wiliwili trees began dying.”

“The Department of Agriculture and the University of Hawaiʻi took action to find a natural predator. Fortunately the team was able to find a parasitoid, another tiny wasp that attacks the gall wasp. They tested it to make sure that it wouldn’t affect any other insect life in Hawaiʻi and they found it was only specific to the gall wasp. They then introduced it on a trial basis around 2008-2009, and it proved to be effective.”

Wiliwili populations began showing signs of recovery, but the fight against the Erythrina gall wasp continues. To learn more about efforts underway to address the gall wasp, visit the Department of Land and Natural Resources website.

Left: Detail of wiliwili bark. Right: Detail of a wiliwili flower.

Top: Detail of wiliwili bark. Bottom: Detail of a wiliwili flower.

Once in a lifetime view

A wiliwili tree in full bloom is a sight to behold. During an aerial survey over the Waiʻanae Mountain Range, Wayson J. of Oʻahu happened upon several blooming wiliwili trees from an entirely different perspective: from above.

“Throughout my years in dryland forest conservation, I’ve been blessed to encounter many unique and rare plant species. None, however, hold a place so dear to my heart as wiliwili.”

“Although I have numerous memories attached to wiliwili trees, the crowning jewel is a moment I recall from the summer of 2022. I was participating in an aerial feral ungulate survey in the Waiʻanae Mountain Range, and as on most flights, I was clenched in fear during most of it (I have a fear of heights). This changed, however, when we happened to fly around a certain mountainside, where I was greeted with the most beautiful sight. Hundreds of wiliwili trees were in bloom with uncountable scarlet and electric green flowers. The colors were so evenly mixed that it almost seemed like a mosaic was painted below my very eyes. I instantly forgot my fear and leaned rather bravely out the side of the door so that I could take in such a once in a lifetime view. I will always remember that one summer I flew over the ulu wiliwili, and how their pua mohala colored the golden mountainside. Kilakila nā Wiliwili o Waiʻanae.”

Interviews were edited for clarity and length. Artwork by Carly Lake.

When we grow Hawaiian native plants and heritage crops, we grow aloha for ʻāina. Adopt one of these cherished plants every third Saturday at our free Grow Aloha plant giveaways at NTBG and partner locations!

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