A Partnership in Pursuit of Revival: Once Nearly Extinct, Ka Palupalu o Kanaloa Sees a Hard-Fought Resurgence

October 8, 2024

By Jon Letman, Bulletin Editor

Anchored in the rain shadow of Haleakalā, Maui’s towering volcano, the smallest of Hawaiʻi’s eight high islands rises from the sea. At just 45 square miles, Kahoʻolawe is less than one-sixteenth the size of Maui. And while the once inhabited island has no permanent settlements today, for centuries it has been considered wahi pana — a storied place — revered as a fertile bed of Hawaiian culture and spirituality.

Kahoʻolawe is known by several names including Kohe Mālamalama O Kanaloa and is closely associated with Kanaloa, an akua (what Western definitions would describe as a god or deity of the ocean). Kahoʻolawe is one of four Hawaiian Islands that as recently as 150,000 years ago comprised a greater land mass called Maui Nui. 

Since European contact, Kahoʻolawe has been subjected to waves of destruction stemming from Western colonization and militarization. In 1793, goats were introduced to the island, and later cattle and sheep, degrading topsoil and causing erosion. In 1941, the island was taken over by the U.S. Navy for use as a ship-to-shore gunnery and bombing range. 

In 1976, a grass roots Hawaiian group called the Protect Kahoʻolawe ʻOhana (PKO) launched direct actions to liberate the island and in the early 1990s the bombing was halted, ordnance removal started, and in 1993 a decade-long process of transferring control of the island back to the state of Hawaiʻi began.

Found on the edge

It was on the vernal equinox of 1992 that NTBG botanists Steve Perlman and Ken Wood were participating in a Nature Conservancy of Hawaiʻi botanical inventory of Kahoʻolawe. The decades of bombing, overgrazing, drought, and erosion had transformed much of the island into a dense, dry hardpan but it still harbored previously undescribed Hawaiian plants. 

While exploring the high cliffs on Kahoʻolawe’s southern coast, Steve and Ken spotted what appeared to be a mixed native coastal shrubland on ʻAleʻale, a small, steep rocky promontory that juts into the water, barely connected to the island by a narrow bridge of crumbling rock and talus.

Recognizing that they both couldn’t go safely, Ken used a 50-meter rope to rappel down to the spire while Steve stayed back to monitor the line just in case. Once he had reached ʻAleʻale, Ken looked up to find what he describes as two unfamiliar “tightly woven shrubs” which resembled members of the legume family (Fabaceae). Climbing some 170 feet above the water, Ken discovered the mysterious shrubs were both flowering and one bore fruit. The two mysterious shrubs were surrounded by the remains of other identical plants — all dead.

That first encounter yielded a collection of viable seeds and plant material which the botanists presented to legume experts at New York Botanical Garden (NYBG) and botanist Ray Fosberg, a specialist in the Hawaiian flora who immediately suggested the discovery might be a “fabulous new genus.”

Further investigation by scientists at NYBG and Fordham University determined that the pollen of this mystery legume was a perfect match for fossilized pollen previously found in core samples from Oʻahu’s north shore and elsewhere in Hawaiʻi. This newly discovered legume, the evidence indicated, was once widely distributed throughout much of Hawaiʻi and probably grew alongside aʻaliʻi (Dodonaea viscosa), loulu (Pritchardia) palms, and other native plants to form coastal dryland forests long before the first humans arrived.

When NTBG scientists Dr. Dave Lorence and Ken Wood published their scientific description of the new legume, Dave named it Kanaloa kahoolawensis in recognition of the island and its namesake deity. This was not only a new species and genus, but was in fact a monotypic genus (having only one species) and Hawaiʻi’s first newly described flowering plant genus since Joseph Rock discovered Hibiscadelphus in 1911.

The plant was given the Hawaiian name Ka Palupalu O Kanaloa in recognition of its softness and the balance it adds to its surroundings. Although considered extinct in the wild, the plant is currently assessed as Critically Endangered with just 16 remaining individuals growing ex situ (outside its natural habitat) at several managed sites on Maui.

After this first encounter with Kanaloa, Ken and other conservation partners took extraordinary measures to keep the two last known wild plants alive, going so far as to deliver water by containers via a perilous helicopter drop off. 

In 2015, the last of the two known wild plants was declared dead but the live material that was collected has been propagated from seed and reproduced by cuttings, growing into new plants which today are being cared for by a network of conservation partners across Hawaiʻi. That group, called the Ka Palupalu O Kanaloa Partnership, has been meeting regularly for over a decade to share information and discuss conservation strategies.

Members of the partnership, including NTBG, have tried to grow Kanaloa in planters, but in some cases these plants succumbed to pests and disease. During the same period, botanists conducted plant surveys on Kahoʻolawe, searching on foot and by air, hoping to find more wild Kanaloa, but to date none have been found. Encouragingly, several successes propagating Kanaloa offer new hope.

Threats and challenges

In recent years, drought has become more persistent and severe in Hawaiʻi, affecting an already arid Kahoʻolawe. The lack of rain, along with the impact of invasive plants like buffle grass (Cenchrus ciliaris) and the spread of small mammals (cats and mice) makes the island a challenging environment for restoration. Furthermore, roughly 70% of the island has been surface cleared of unexploded ordnance but the risk remains, and live rounds are still found on land, a problem exacerbated by erosion. Bombs can still wash up along the shoreline at any time.

Jamie Bruch, a conservation biologist with the Kahoʻolawe Island Reserve Commission (KIRC), has been working with NTBG and other partners to collect Kanaloa seed and genetic material. He explains that the survival of Kanaloa is an important element of restoring Kahoʻolawe’s dryland forests.

KIRC has co-authored a management plan that serves as a guiding document for the partnership.

Guardians of Kanaloa

At the center of Kanaloa conservation is Anna Palomino, a senior horticulturist with the University of Hawaiʻi Center for Conservation Research and Training. Anna grows rare and endangered species for outplanting in the wild and has been working with Kanaloa since 2008 when she was given a lone seed from Ken Wood.

Recently, one hot summer morning, Anna took time out to introduce the young Kanaloa plants she is tasked with caring for under a contract from Hawaiʻi’s Division of Forestry and Wildlife (DOFAW). She was joined by CJ Elizares who works with PKO, leading a crew of young Native Hawaiian conservationists to remove invasive plants reintroduce native near-shore species in Makena on southwest Maui.

Seated on low black plastic nursery benches beneath a shade cloth, Anna and CJ explain that with so few Kanaloa remaining, there is tremendous pressure to prevent it from going extinct.  Anna describes the challenges of growing this most-demanding species. Kanaloa, she says, goes through many different growth stages and is frequently dormant. It’s sensitive to pesticides and prone to root rot. Rats love the seeds. It’s also highly susceptible to insects, spider mites, snow scale, fungal diseases, and other plant pathogens. 

As a slow-growing woody shrub, Kanaloa cannot be cloned as easily as herbaceous plants. When Kanaloa flowers (infrequently), it produces a ball-shaped cluster of mostly male flowers, with female flowers fewer in number and difficult to find, making pollination opportunities rare. 

Efforts to air layer and graft Kanaloa have been mostly unsuccessful and cloning from cuttings has had limited success (two cloned plants live beside the oldest “mother plant”), but in general, it’s difficult to obtain planting material. Now, with just 16 plants, the diversity and vigor found in a large plant population is absent, making recovery even more challenging. 

“It’s a pretty complicated plant,” Anna says, with a mix of resignation and admiration.

Today’s small but resurgent Kanaloa population ranges from the largest mature “mother plant” which has provided seed and pollen to more than a dozen young plants. Live plant tissue is stored at the University of Hawaiʻi’s Lyon Arboretum with frozen pollen kept in storage at a USDA facility in Colorado.

In the 15 years that she has worked at this plant facility, Anna has watched as the environment has grown drier and warmer. In August 2023, ferocious winds destroyed one greenhouse, and the subsequent wildfires that razed so much land on Maui, came perilously close to a site where more than half the entire population is growing.

But there have been great successes too.

In 2016, scientists at Lyon Arboretum made a major breakthrough when, after many attempts to grow from seed and other techniques, they were able to propagate plants from cuttings. 

Then, in 2020, Anna had her own breakthrough when the mother plant produced male and female flowers with many seed pods. With more than 20 viable seeds, Anna was able to propagate and start seedlings, more than a dozen of which still survive today.  

Since she started caring for Kanaloa, Anna has closely observed every aspect of the plant, taking meticulous notes and making drawings to record the plant’s behavior and habits. For example, when the plants were at their most vulnerable state, she took them indoors at night and in doing so, noticed that the leaves fold closed until morning. With such a rare, virtually unknown plant, her notebook has become her own guidebook based on firsthand experience.

In 2023, a lone Kanaloa accession with a single seed was withdrawn from NTBG’s seed bank and hand delivered to Kahanu Garden and Preserve director Mike Opgenorth who brought it to Anna. She successfully germinated the seed, producing what is now a year-and-a-half old plant.

Today, this “all of the above” strategy continues, trying to get plants to flower and seed with efforts to propagate from cuttings and tissue culture at Lyon Arboretum’s tissue culture lab. Additionally, DOFAW-operated fog-bench propagation system on Oʻahu offers new hope for Kanaloa cuttings. 

Caring for a monotypic genus that was down to a single known individual, she says, has been a huge responsibility with the threat of extinction a heavy burden to bear alone which is why this group approach to conservation is so important.

From warriors to healers

CJ explains how, just as a new era was dawning on Kahoʻolawe in the early 1990s and PKO was contemplating its own future, along came Kanaloa, a plant in need of help. “We realized that we needed to shift our mindset and vision from being warriors to fight for the island to be healers of the land and work for the plant.” 

Rather than looking at Kanaloa with pity, as if it were the last of its kind, CJ takes an alternate view, saying these will be the first plants to go back into the soil, to grow and repopulate the island. He and his crew look to the plant for guidance, taking cues from Kanaloa. When a particular plant grows tall and straight, he says it is the time to stand up and be assertive. If another plant grows low to the ground, it may be time to lay low.

Ka Palupalu O Kanaloa, represents more than the ocean and an island, says CJ. Kanaloa is a kinolau (living embodiment) of the akua bearing the same name. “When plants have names that are attributed to something that we can identify with…to dedicate a name to care for the species is important.” Just as Anna cares for the plants like her children, he says, “we have that relationship to the plants.” Kanaloa is “part of our system, part of our people, part of our fiber of who we are.”

Also on Maui, NTBG’s Kahanu Garden staff are playing an active role in caring for three plants being grown in a wire enclosure to protect against rats. 

As Mike Opgenorth inspects the plants, he sees growing Kanaloa in multiple sites that vary in elevation, temperature, and rainfall as a way to better inform decisions about potential suitable future habitats. He asks, was the hot, dry, rocky habitat of ʻAleʻale the ideal environment for Kanaloa, or did it just happen to be the last place it was found alive?

This lack of historical data and guesswork is countered by robust discussions among the partnership, Mike says. Doing so also helps share the responsibility to care for the plants among multiple stakeholders. An important element of this inter-agency cooperation is the inclusion of cultural practitioners and the integration of conservation to place.

Pursuing an end goal

What is the end goal for conserving Kanaloa? For Anna, it’s simple: she wants to see more flowering, more pollination, more viable seeds, and more plants.

Building on the partnership’s recent successes, CJ is eager to see Kanaloa plants translocated from managed facilities to being planted out on Kahoʻolawe. “My hope is not a bleak one. My hope is that’s where they belong, that’s where they should go, and that’s my goal.” 

KIRC’s Jamie Bruch says it would be ideal to have three propagation facilities, each with 100 plants before the others were returned to the wild. Having 300 plants would increase the likelihood that a Kanaloa population could be re-established on Kahoʻolawe and in habitats where it was once abundant. 

Matt Keir, a botanist with Hawaiʻi’s Department of Land and Natural Resources’ Division of Forestry and Wildlife, manages the Plant Extinction Prevention Program (PEPP) which specializes in conserving Critically Endangered Species with 50 or fewer wild individuals. Having worked with Kanaloa for 25 years, he concedes that “the future of this plant is with people.” 

Ideally though, Matt hopes the plant will be returned to a functioning ecosystem where it can survive with as little intervention as possible. Before that can happen, he says it makes sense to have a large source of cultivated plants that can provide planting material because it is almost guaranteed that a certain number of outplanted individuals will not survive.

Another outcome of group efforts to perpetuate Kanaloa is to strengthen the relationships forged between diverse interests who each have their own approach, experience, and abilities, but share the goal of preserving plant life in Hawaiʻi. That conservation ethic can be replicated and passed down to the next generation.

Mike Opgenorth says the partnership is vital for survival of Kanaloa because even the best horticulturist in the world will not have success 100% of the time. He sees great benefits to having multiple perspectives working with such a rare plant. It’s not any one organization, agency, or individual, it’s a team effort that shares the responsibility for perpetuating the plant.

“We think it’s a good case study for what we could do for other species that we’re trying to protect that require this level of attention,” Mike says. What’s really important about Kanaloa conservation, he adds, is not who grows the plant, but that it grows.

[1] Maui Nui (literally “big Maui”), was comprised of Maui, Molokaʻi, Lanaʻi, and Kahoʻolawe, and estimated to have measured 5,640 sq. miles some 1.2 million years ago, according to the U.S. Geological Survey.

[2]  Read Ken Wood’s account of botanizing on ʻAleʻale in The Bulletin Vol. XXXIV No. 1 (Winter-Spring 2018)

[3] Conservation paleobiologist Dr. David Burney played a key role in identifying Kanaloa’s pollen. Dr. Burney later served as NTBG’s director of conservation.