Becoming Plant Passionate

People need plants. They are the root cause of our health, habitat, and happiness. More than ever, plants need you. Join us this fall as we explore how cultivating deeper connections with plants can grow a brighter tomorrow for our ecosystems and communities.


If you haven’t thought about plants today, you’re certainly not alone. Even though plants make our everyday possible, many of us seldom pause to appreciate just how important they are to our health and overall wellbeing. Plants and people go together. In the Hawaiian worldview, kalo (taro) is an older sibling who continues to feed and nourish communities across the islands. Ola ke kalo, ola ke kānaka; ola ke kānaka, ola ke kalo is a Hawaiian proverb that means if kalo lives, Hawaiians live; if Hawaiians live, kalo lives. 

(L) Breadfruit being gathered at the Regenerative Organic Breadfruit Agroforest. (R) Noah Kaaumoana-Texeira gathering kalo (taro)

“In some Native languages, the term for plants translates to ‘those who take care of us,’” says Potawatomi botanist and Braiding Sweetgrass author, Robin Wall Kimmerer. From lowering stress and anxiety, to producing cancer-fighting compounds and healthy regenerative agriculture systems, plants are often our best teacher and most helpful remedy. Increasing our awareness and recognition of plants is the first step in protecting our precious biodiversity. Our future depends on it.

becoming plant passionate

Lahela Chandler Correa, Visitor Program Manager at Limahuli Garden & Preserve

Becoming Plant Passionate

Plants feed, shelter, heal, and fuel us. They inspire art, help us express emotion, and guide many of our cultural and spiritual practices. Data also shows that spending time in nature improves our mental and physical health. So, why do we often overlook their importance to all life on Earth and limit our interest in plant conservation? 

Researchers have noted a growing indifference to plants. There are many reasons for plant unawareness. In urban areas, many people lack equitable access to plants, parks, and natural spaces. Plants are underrepresented in education. From kindergarten to college, plant science is fading from curriculum and school programs. It also has to do with what’s inside our heads: since most plant life is similar in color, mostly stationary, and densely packed, our brains can be hardwired to lump them together instead of noting their differences. In other words, many of us tend to see the forest and not the trees. Importantly, awareness for plants differs across cultures. Most research on the topic has been done in Western societies, whereas Indigenous communities often have a deep and fundamental awareness of plants.

We must increase our awareness and empathy for the plant life surrounding and supporting us. In his 1968 speech to the International Union for Conservation of Nature, Senegalese conservationist Baba Dioum said, “In the end, we will conserve only what we love; we will love only what we understand and we will understand only what we are taught.” The more we engage with plants and experience their positive effects on our health and wellbeing, the more likely we are to protect them. It’s time to become plant passionate.

(L) Dr. Nina Ronsted examines an herbarium voucher of Madagascar periwinkle. (R) Close-up of Madagascar periwinkle

Modern Medicine and the Power of Plants

Plants have always healed us and today are found in a quarter of our medicines. Yet, most drug researchers focus on synthetically-derived medicines. Despite technological progress, the number of new drugs brought to the market is in decline. However, drug discovery from plants and other natural products continues to be highly productive and effective. 

“Today, we are still challenged by a long list of unmet medical needs for safe and effective medicines,” said Nina Ronsted, NTBG’s Director of Science and Conservation. “One of the grand challenges for humankind remains the identification of new leads for pharmaceutical research,” she continued. The need for new leads is just one reason plant science and conservation are essential not only to the health of our planet but also to our people. “It is not easy to guess which plants might cure which diseases,” said Nina. “As extinction accelerates, we risk losing potential medicines even before they are discovered,” she concluded. 

Director of Science and Conservation, Dr. Nina Ronsted, admires Madagascar periwinkle flowers

In recent history, compounds from the Madagascar periwinkle have increased the survival rate of childhood leukemia from 10% to 90%. In addition, a compound initially found in Pacific Yew trees (Taxus brevifolia), is the cancer-fighting component of Taxol. This drug inhibits the rapid multiplication of  cancer cells. Today, Taxol is on the World Health Organization’s list of Essential Medicines and is one of the most effective drugs for treating multiple forms of cancer. 

“The potentially useful compounds that plants have developed over time in response to herbivores overcoming their effects are increasingly complex and specialized,” noted Nina. “Many of these compounds may affect humans and become cures for diseases,” she finished. 

With time, plant research and conservation will reveal more about the connection between plant compounds and human health. But what can we do today to strengthen our connection and improve our health right now? The answer is a walk in the park (or garden!).

plant passionate

Noel Dickinson, Breadfruit Institute Coordinator, holding breadfruit in the Regenerative Organic Breadfruit Agroforest (ROBA)

Healthy Plants, Healthy Planet

On any given weekday, you’ll find Noel Dickinson of NTBG’s Breadfruit Institute tending to the trees and edible understory plants in the Regenerative Organic Breadfruit Agroforestry (ROBA) demonstration in NTBG’s McBryde Garden. Breadfruit has long been an important staple crop and a primary component of traditional agroforestry systems in Oceania. In addition to providing food and goods, breadfruit agroforests offer broad ecosystem benefits such as soil and water conservation and biodiversity maintenance essential to long-term island habitation. ROBA is a two-acre display garden and model for implementing breadfruit agroforestry in tropical regions and areas of food scarcity worldwide. 

For Noel, breadfruit agroforestry does more than produce nutritious food and regenerate land degraded by erosion, compaction, and loss of organic matter. It nurtures her, builds relationships, and provides an opportunity to learn and grow. “Plants are a huge part of my life, personally and professionally, and breadfruit has had a big impact on me,” said Noel. “Through my work with the Breadfruit Institute at NTBG, I have been able to learn new things as well as literally share the fruits of my labor with my community,” she effused. “I have also, at times, been given a platform to represent the gardens,” she said. “Being an ambassador for not only breadfruit but also NTBG is a great joy for me.” 

Studies show it’s not just Noel benefitting from time spent with plants. Plants can generate happiness, reduce stress, and increase positive energy in the home. In addition, access to parks and outdoor spaces increases rates of physical activity and overall healthiness. Research also shows that people who spend more time around plants have better relationships with the people around them. 

(L) A ripening breadfruit amongst colorful ti leaves in the Regenerative Organic Breadfruit Agroforest. (R) Noel Dickinson, Breadfruit Institute Coordinator, gathering breadfruit in ROBA

Healthy Today, Here for the Future

Plants and people are inextricably linked. From everyday wellbeing to the next medical breakthrough, we need plants to maintain our health and the health of our planet today. As we navigate and study the effects of climate change, our future also depends on our ability to recognize the plant life surrounding us, learn from it and investigate solutions for what lies ahead.

People need plants. Plants need you.

Plants nourish our ecosystems and communities in countless ways. When we care for plants, they continue caring for us. Help us grow a brighter tomorrow for tropical plants.  

Alula Featured in Applications in Plant Science

NTBG’s latest alula research was recently published by Applications in Plant Sciences

For nearly six decades, the National Tropical Botanical Garden (NTBG) has been saving plants. Among the many rare and endangered plant species NTBG is known for conserving is the genus Brighamia, a member of the bellflower family (Campanulaceae), endemic to (found only in) Hawaii. Called alula in Hawaiian, both species — Brighamia insignis and Brighamia rockii — grow on Hawaii’s steep slopes and high sea cliffs. In the 1990s, National Geographic famously photographed two NTBG botanists rappelling over Kauai’s Na Pali coast, collecting plant material to propagate in the nursery.

In the decades since, Brighamia rockii has dwindled to just eleven known plants that cling to the cliffs of Molokai. Its close relative, Brighamia insignis, last seen on Kauai, is now believed to be extinct in the wild. However, thanks to the efforts of NTBG and others, the alula has been successfully cultivated and is even commercially available as a houseplant in Europe and elsewhere. NTBG staff and scientists continue to conserve and study the alula with ongoing research featured in the most recent issue of Applications in Plant Sciences, a publication of the Botanical Society of America.

applications in plant science
Seana Walsh, Conservation Biologist, inspecting Brighamia insignis in NTBG’s Conservation Nursery

In an article co-lead authored by NTBG conservation biologist Seana Walsh, scientists show how the adaptation of pedigrees used by the zoo community can be used to manage botanical garden collections and reduce inbreeding, resulting in healthier plants. Researchers selected Brighamia insignis as their case study. Their findings illustrate the importance of maintaining diversity through strategic cross pollinations. 

In the same issue, seedbank and laboratory manager Dustin Wolkis lead authored an article about seed dormancy and germination of Brighamia rockii. The authors found that a high percentage of the seeds germinate over a range of temperatures and are suitable for propagating from seed for conservation. Research suggests these seeds are unlikely to form a long-live soil seed bank and will need human intervention to be reintroduced into the wild.

By continuing to study and conserve this charismatic native Hawaiian plant genus, collaborating with likeminded organizations and institutions, NTBG is playing a leading role in advancing the understanding of rare and endangered plants and ensuring the preservation of irreplaceable biodiversity.

Hope Takes Root for Kauai’s Rare Plants

Advancements in drone technology aid in rescuing rare cliff-dwelling plants

The summer of 2022 started off with hopeful celebration at our Conservation Nursery on Kauai as three different critically endangered plant taxa collected by the Mamba drone arm set roots from cuttings – laukahi (Plantago princeps var. anomala), akoko (Euphorbia eleanoriae), and Lysimachia iniki

The Mamba, developed by Outreach Robotics with the help of NTBG scientists, is able to collect rare plants from otherwise inaccessible places. Mamba also allows for a much faster retrieval time. What used to take hours of hiking and rappelling to collect plant material, now takes minutes with the Mamba. This result is fresher plant material arriving at our Conservation Nursery and an increase in the likelihood of successful propagation. 

Think of it like rescuing an imperiled person from a remote spot. If you hike to reach the person and carry them to safety on a stretcher, the chance that they are under additional stress is much higher than quickly airlifting them. The sooner we can get the patient (plant) back to the emergency room (our Conservation Nursery), the greater chance of survival.

While attempting to set roots from cuttings in both Lysimachia iniki and akoko has occurred before, it was the first known attempt to do so with laukahi due to its rarity. That all three sprouted roots is an inspiring accomplishment for the Mamba field collection and nursery teams, providing further proof of how new technology can advance rare plant conservation. 

rare plants
Laukahi (Plantago princeps var. anomala) with flower stem growing in NTBG’s Conservation Nursery on Kauai

Laukahi (Plantago princeps var. anomala)

Laukahi (Plantago princeps var. anomala) is a small erect or ascending woody shrub that grows on steep slopes and cliffs in wet forests in the Upper Hanapepe and Kalalau valleys on the Hawaiian island of Kauai. Curiously, laukahi is one of more than 250 species in the genus Plantago, largely temperate in distribution, but also occurring at high altitudes in tropical areas and on oceanic islands like Hawaii. While some consider Plantago species like Plantago major to be invasive or ‘weedy,’ Kauai’s Plantago princeps is Critically Endangered with less than 50 individuals known to occur in the wild. 

Further field collection trips with Mamba could have a big impact on the future of critically endangered plants like laukahiThe original cutting is doing well at the nursery and even recently developed a flower stem. A flower means seeds, and seeds mean increased hope for future restoration in the plant’s natural habitat.  

rare plants
Fresh Lysimachia iniki cutting being processed in NTBG’s Conservation Nursery on Kauai

Lysimachia iniki

Past samples of Lysimachia iniki brought to the Conservation Nursery were fragments of plants that had fallen from the sheer cliffs below Kauai’s summit after storms. Incidentally, this is how the species got its name. Lysimachia iniki‘s discovery occurred after Hurricane Iniki’s devastating winds dislodged the native plant from its steep habitat. No past plant fragments brought back to our nursery had ever survived. That is until now. 

Two Lysimachia iniki propagules are thriving under the care of our staff in the Conservation Nursery. There is only one known population of Lysimachia iniki, underlining the importance of this major breakthrough in the conservation of this Critically Endangered Kauai endemic plant. 

Kadua st-johnii growing in NTBG’s Conservation Nursery on Kauai

Additional Success for Rare Plants

The Mamba has brought additional success beyond laukahi and Lysimachia iniki. A rare Rubiaceae, Kadua st-johnii, grew from a seed collected off of a cutting and a less rare Lysimachia hillebrandii also took root. Lysimachia, a member of the Primrose family, is often difficult to grow from cuttings. The successful rooting of Lysimachia hillebrandii in our Conservation Nursery reinforces that the speed with which Mamba retrieves plant material directly affects survivorship in the nursery.

There have been some setbacks. Akoko (Euphorbia eleanoriae) survived for four months after setting roots. While this specimen did not make it to maturity, it is the first time the species set roots in cultivation. The team at the Conservation Nursery plans to build on the knowledge gained from the first attempt to try again with future field collections. 

Ultimately, the Mamba allows us to reach rare plants that are otherwise unreachable. For some of these cliff-dwelling species or any plants that grow in hard to reach areas, these developments in drone technology may be the best hope for their continued survival. “The use of drones also allows a fast turnaround for processing cuttings and placing them in our mist-house or in a temperature controlled location for protection,” says NTBG Nursery Manager, Rhian Campbell. “As we continue to develop protocols for the handling of these cuttings and learn everything we can about propagating these extremely rare species, we are also likely to become more successful with them over time.”

Nothing Beyond Reach

Cutting edge drone technology leaves nothing beyond reach.

By Ben Nyberg, GIS and Drone Program Coordinator

drone technology
Photo by Ben Nyberg

NTBG members who have been supporting our work for years know that the discovery, collection, and conservation of rare plants is central to our mission. Roughly 90 percent of the Hawaiian flora is found nowhere else on Earth, and so saving these plants is a great responsibility. But on an island like Kauai, where many rare plants grow in steep terrain and sheer cliffs, they can be impossible to access on foot.

For decades, NTBG has used traditional rappelling techniques to reach endangered cliff-dwelling plants like alula (Brighamia rockii) but in some cases, the plants are inaccessible to even the most experienced rappellers. In 2016, NTBG began experimenting with drone technology to discover plants that were otherwise beyond our reach.

Soon after our drone program began, we were encouraged by a number of rare plant discoveries in remote, previously unexplored cliff habitat. Drone technology was an exciting new tool that revealed rare plant populations we never imagined we could explore, but even as we made progress, we asked, “what’s next?”

The answer came when we were approached by a group of Canadian researchers from the University of Sherbrooke in Quebec who were grappling with similar challenges. The researchers had started a company, Outreach Robotics, and developed a drone mechanism they called DeLeaves that could collect plant material from treetops.

Their drone carried a tool suspended below it that can grasp and cut plants mid-air. DeLeaves proved highly effective for collecting plants directly below a drone, but could it be used on Hawaii’s sheer cliffs?

Field team preparing for a trial run along the sheer cliffs of Waimea Canyon. Photo by Guillaume Charron, Outreach Robotics

Excited by the chance to collaborate with the robotics team, we applied for a grant from the National Geographic Society with the hope of funding the development of a horizontal collecting arm. Our goal was to design a robotic arm that would enable us to collect seeds and cuttings from small, often fragile cliff dwelling species in Hawaii. When our application was approved, we quickly started the design process.

In our attempt to overcome the challenges of Hawaii’s extreme cliffs, we explored everything from long, extendable poles to semi-rigid vacuum hoses, and even one design that snapped like a clam shell. We were planning for our initial field trials when the COVID pandemic brought our work to a halt.

What at first appeared to be a major setback, later proved to be to our advantage. Travel restrictions delayed field trials for almost two years, but that allowed the team at the robotics lab in Quebec to build, test, and redesign the collecting arm without disruption. In the fall of 2021, as international travel was reopening, the team unveiled the MAMBA (Multi-Use Aerial Manipulator Bidirectionally Actuated). The draft design featured two independently functioning components — a lifting drone and the MAMBA mechanism.

MAMBA is suspended below the lifting drone but, unlike the earlier DeLeaves design, it has propellers that move the collecting arm forward and back like a pendulum. The device has a separate controller and remote video feed, allowing the MAMBA pilot to clearly see minute details within inches of the plant and cutting piece. The sampling head rotates in multiple directions, enabling the pilot the ability to align with and collect their branch of choice.

drone technology
The robotic sampling arm after is collected Na Pali akoko (Isodendrion pyrifolium)

In October 2021, we initiated the first set of field trials on Kauai. Within a few hours of test flights in McBryde Garden, we felt comfortable deploying MAMBA into the wild. We were thrilled to find the device was stable, precise, and easy to operate. Focusing on target species such as akoko (Euphorbia eleanoriae), dwarf iliau (Wilkesia hobdyi), and hau kuahiwi (Hibiscadelphus distans), the MAMBA performed well, allowing us to secure collections from each species, in some cases from more than half a mile away.

Following our initial trial flights, the robotics team returned to Quebec where they continued to refine MAMBA. In March 2022 the team returned to Kauai ready to help us attempt to collect from target species which were particularly difficult subjects due to the plant’s growth habit or location.

These Kauai endemic species, all Critically Endangered, include Lysimachia inki, Kadua st-johnii, Lysimachia scopulensis, and laukahi (Plantago princeps var. anomala).

Lysimachia iniki Photo by Ben Nyberg

To better appreciate the challenges of collecting these extremely rare plants with this new technology, consider the case of Lysimachia iniki which grows on 3,000-foot high cliffs below Kauai’s summit, one of the wettest places on Earth. The extreme terrain and rainfall make this a particularly difficult area to operate drones.

After lugging the cumbersome equipment along muddy slopes and across a rushing stream, we were able to use a spotting scope to find plants with flowers and seeds. Climbing into the mist, the drone carried MAMBA to our target plants where we successfully collected a cutting from the sheer green wall and delivered it to us far below.

To our knowledge, the MAMBA collection of L. iniki was a first. The plant had been collected opportunistically after storms for the last 30 years, but our intentional collection yielded a large number of seeds from a healthy specimen, allowing us to deposit this invaluable collection to our seed bank and cuttings to our nursery where they rooted in captivity for the first time.

Understanding the distribution and abundance of rare and endangered plants is a critical first step in their conservation.

Ben Nyberg, GIS and Drone Program Coordinator

Another example of how drone technology is advancing rare plant conservation is our use of MAMBA to collect a sample from the extremely rare wahine noho kula (Isodendrion pyrifolium), a plant we were unable to identify by drone survey alone. After watching the MAMBA remotely cut and collect the plant, our excitement swelled as the drone returned. There is an undeniable thrill in extending one’s human hand to receive a botanical treasure from a robotic hand.

Previously documented on Niihau, Maui, Lanai and Hawaii Island in the mid 19th century, Isodendrion pyrifolium was thought to be extinct for more than a century until it was rediscovered on Hawaii in 1993. Another population was found on Oahu in 2015, but it was the MAMBA that allowed us to actually collect the species for the first time on Kauai.

Understanding the distribution and abundance of rare and endangered plants is a critical first step in their conservation. Drone technology makes this possible. Collecting seeds and cuttings from remote plant populations is the next step. Now drones can do that too. A third critical step in the conservation of plants is returning species to their natural habitat.

New projects now underway will eventually allow us to sow seeds onto inaccessible steep slopes. What we thought was impossible just five years ago is now reality. Armed with these new tools, a commitment to cooperation, and the determination to succeed, we are hopeful that these new discoveries will continue to positively impact plant conservation in Hawaii and far beyond.

Introducing the Mamba

Kauai, Hawaii

Researchers in Hawaii and Canada have developed a robotic arm that remotely collects endangered plants from high cliffs

Scientists at the National Tropical Botanical Garden (NTBG) in Hawaii, along with engineers at Outreach Robotics and researchers from the University of Sherbrooke in Quebec, Canada have designed a remotely controlled arm that can collect rare and endangered plants while suspended by a drone.

Their progress has been published in the journal Nature – Scientific Reports, documenting how the new technology is redefining rare plant conservation on high cliffs and other extreme habitat.

The partnership centers around an aerial robotic sampler roughly the length of a fishing rod equipped with eight propellers and a cutting mechanism which is suspended by a drone. The arm, called Mamba, can be operated remotely up to one mile (1.6 km) away. In flight trials, NTBG scientists and their partners have successfully collected seeds and cuttings from remote plant populations of extremely rare native species such as Lysimachia iniki and Isodendrion pyrifolium which grow on sheer cliff faces that are otherwise inaccessible.

NTBG drone specialist Ben Nyberg calls the technology “ground-breaking” and said, “this combination of robotics and botany is exciting, and is already having an amazing impact both in species conservation and the knowledge we’re gaining about cliff environments.”

Once retrieved by Mamba, the plants are recorded and brought to NTBG facilities where seeds are stored in a seed bank for conservation and research. Other seeds and cuttings are propagated in the nursery where they are grown and later used for restoration projects and returned to the wild.

NTBG nursery manager Rhian Campbell said the new technology can potentially increase success rates in growing rare plants because wild cuttings reach the conservation nursery much faster and in better condition than if they had been retrieved by hand. “The amount of time fragile cuttings spend under stress is minimized. Mamba allows us to collect multiple species very efficiently in a fraction of the time it used to take,” said Campbell.

NTBG is based on Kauai which is recognized as a biodiversity hotspot and is the oldest of Hawaii’s inhabited islands. Kauai is home to 255 plant species found nowhere else on Earth, nearly 90 percent of which are classified as Endangered or Critically Endangered based on IUCN Red List criteria. The remaining ten percent are extinct or nearly extinct in the wild.

For decades, NTBG botanists have used helicopters, rappelling, and rough terrain roping techniques to discover and collect plant material from some of the world’s rarest and most difficult to reach plant species. 

Since 2016, NTBG has been using drones to discover rare plant populations previously thought to have gone extinct or otherwise unknown. NTBG’s collaboration with Outreach Robotics and the University of Sherbrooke in Quebec began in 2020.  

Trial flights using Mamba include partnering with the State of Hawaii’s Department of Land and Natural Resources Division of Forestry and Wildlife (DOFAW) and the Plant Extinction Prevention Program. Adam Williams, a DOFAW botanist said, “Mamba has exceeded our wildest expectations, turning science fiction into reality. Surveying and collecting from a thousand-foot-high cliff from a mile away is just mind-blowing.”

Calling Mamba a “game changer,” NTBG’s Nyberg added, “it allows us to reach critically endangered species that are down to just a few individuals. It can be the difference between extinction and survival.”

The mission of the National Tropical Botanical Garden is to enrich life through discovery, scientific research, conservation, and education by perpetuating the survival of plants, ecosystems, and cultural knowledge of tropical regions.

Press kit with content and guidelines available here.

Learn more about the work of the National Tropical Botanical Garden at www.ntbg.org.

Learn more about NTBG’s drone program at www.ntbg.org/science/conservation/drones/.

Learn more about the work of Outreach Robotics at www.outreachrobotics.com.

For media inquiries, contact: media@ntbg.org

Kō (Saccharum officinarum)

Eye On Plants

Among the two dozen or so ‘canoe plants’ introduced to Hawaiʻi by the first Polynesian voyagers, sugarcane is one of the most widely grown in the tropical world. Called kō in Hawaiian, elsewhere sugarcane is known as to (Marquesas, Tonga), tolo (Samoa, Tuvalu), and dovu (Fiji). This sturdy member of the Poaceae (grass family) may have been first cultivated in Papua New Guinea, possibly originating as Saccharum spontaneum, a relative of S. officinarum.

Ko (Saccharum officinarum)
Hāpai Sugercane Photo by Jon Letman

Kō (Saccharum spontaneum) is valued for its sucrose-rich fibrous pulp which is used to sweeten food, drinks, and medicine or (as old-timers will tell you) cut fresh with a cane knife and chewed in the field. For early Hawaiians, kō was more than a sweetener. It provided thatching, mulch, compost, an ornamental wind break, and served as a soil stabilizer.

NTBG senior research botanist Dr. David Lorence first encountered sugarcane as a Peace Corps volunteer in 1970, working in a program of agricultural diversification with the Mauritius Sugarcane Industry Research Institute. Like Hawaiʻi, the southwest Indian Ocean island nation supported a vibrant sugarcane industry before it turned toward tourism.

Dave Lorence notes that while sugarcane has played a central role in the economies and development of many tropical countries, it also bears a darker history based on slavery and indentured laborers. Fortunes were made and empires built on the backs of laborers who toiled in cane fields doing back-breaking work, cutting and stacking cane by hand in dirty, sometimes dangerous conditions.

Furthermore, the industry was known for its insatiable (and often destructive) thirst for water, waste runoff, heavy fertilization, and industrial pollution. During harvest time, when drier, lower leaves were burned off the cane, Hawaiʻi’s skies blackened with soot and ash.

Hawaii’s own industrial sugarcane industry began on Kauaʻi in the town of Kōloa and quickly spread across the islands, fueling the migration of workers from Asia, the Caribbean, and beyond, leading to cultural and societal shifts that remain today.

Despite its checkered past, many in Hawaiʻi harbor deep affection for ko, and rue wistfully for the recent past when the days grew shorter, the cane grew taller, and its silvery tassels blew in the wind, signaling autumn harvest, the rising of the Pleiades (Na huihui o makaliʻi), and return of the Hawaiian Makahiki season.

In 2022, NTBG hosted Dr. Noa Kekuewa Lincoln, a Hawaiian crop specialist at the University of Hawaiʻi. Noa worked closely with NTBG staff to verify the provenance and identity of the Garden’s kō collection. Presently, NTBG has 11 sugarcane cultivars in McBryde Garden, eight at Limahuli Garden, and an estimated 27 at Kahanu Garden.

Kahanu Garden director Mike Opgenorth worked with Noa to verify cultivars and identify duplicates among the garden’s collection. Mike says that Hawaiian kō varieties have adapted to thrive in very specific microclimates which can make growing them together in one collection a challenge. With its mix of traditional Hawaiian cultivars and other, more recent ones, Mike says Kahanu Garden is a great place for people to experience the splendor of sugarcane growing in robust clumps.

Mike spoke of the importance of the plants in perpetuating cultural knowledge, naming a little-known variety called Koeli lima a o Halalii which translates as the hand-dug cane of Halaliʻi, a rare white-stalked cane known to grow in the sandy dunes along Halaliʻi, a seasonal lake on the island of Niʻihau. When exposed to the sun, the cane’s stripes turn lime green and iridescent pink. Nourished by Niʻihau’s freshwater springs and periodic rainfall from Mt. Paniau, the legendary ko is mentioned in the centuries-old stories and chants of Niʻihau

“The Hawaiians name everything and have a reason for doing that. Every wind and every rain has a name. Every cultivar of every canoe plant also has a name,” said Mike DeMotta. “But if you don’t know the name, you don’t know what you can do with it.”

A Global Partnership That Feeds

By Jon Letman, Editor

Posted on a wall in the office of the Breadfruit Institute at National Tropical Botanical Garden headquarters, a world map is marked by a bright green band indicating where breadfruit grows best. That band represents the potential to improve food security, increase reforestation, and bolster economic self-sufficiency.

One of the Breadfruit Institute’s most successful partnerships is with the Trees That Feed Foundation (“Trees That Feed”). Co-founded in 2008 by wife and husband Mary and Mike McLaughlin, two Jamaican-born breadfruit enthusiasts, Trees That Feed was established as a non-profit organization with the encouragement and support of NTBG Trustee Emeritus Douglas McBryde Kinney who also introduced Mary and Mike to Dr. Diane Ragone, director of the Breadfruit Institute.

Mike and Mary wanted to do something about climate change, environmental degradation, and global hunger, while creating economic opportunities. With breadfruit, they found they could address all.

As Trees That Feed grew, two promising breadfruit varieties—the Samoan Maʻafala and Tahitian Otea—caught Mary and Mike’s attention. After years of collaboration between Diane Ragone and Dr. Susan Murch, a plant chemist and tissue culture researcher at the University of British Columbia – Okanagan, Maʻafala and Otea were identified for their vigor, nutritional value, and suitability for mass micropropagation and global distribution.

Diane, who has spent more than 30 years studying and collecting breadfruit varieties from 50 Pacific islands, built the largest, most diverse collection of breadfruit varieties in the world. Since establishing a partnership with the Breadfruit Institute, Trees That Feed has distributed tens of thousands of micropropagated breadfruit trees originating from NTBG’s conservation collection to at least 18 countries and territories.

Since 2018, Trees That Feed has purchased breadfruit treelets from Tissue Grown, a California-based plant tissue culture company which grows the Breadfruit Institute-sourced Maʻafala that Mary and Mike have mostly donated to growers in Central America, the Caribbean, and Africa. A portion of the trees are sold commercially which helps support NTBG and the countries of origin.

South Pacific vibe

Tissue Grown’s president Carolyn Sluis explains how the tissue culture-raised breadfruit treelets are grown in peat and vermiculite plugs without soil. After acclimatizing in the greenhouse for six weeks, they are distributed around the world in flats of 72 saplings. Before the plants can be shipped, Tissue Grown must complete complicated and time-consuming shipping protocols through their local agriculture department. Once approved, the trees are sent by air and hand-delivered to overseas destinations by operations manager Karin Bolczyk.

Despite two years of the COVID-19 pandemic, Tissue Grown grew more than 100,000 Maʻafala and Otea in 2020-21. Last December, they shipped 1,800 Otea to Kenya with another shipment of three flats to Guinea in January 2022.

Calling Diane Ragone’s enthusiasm “infectious,” Carolyn hopes breadfruit will gain a foothold in more countries. For a company more accustomed to growing walnuts, pistachios, and cherries, breadfruit is somewhat unusual, but Carolyn and Karin agree that Maʻafala and Otea, with their “South Pacific vibe,” make breadfruit an irresistible feel-good crop.

Farmer Nate Olive checks one of his breadfruit trees on St. Croix in the U.S. Virgin Islands. Photo by Ridge to Reef Farm

Pacific connection

One of the farmers Karin has delivered breadfruit to was Nate Olive, owner of the 130-acre Ridge to Reef farm on St. Croix in the U.S. Virgin Islands. In the aftermath of the category-5 Hurricane Maria which devastated the region in 2017, Nate shifted his focus to growing breadfruit to replace lost trees and which he says proved to be a great morale booster.

Coordinating with Trees That Feed and Tissue Grown, Nate has already distributed some 3,500 donated trees on St. Croix, St. Thomas, and St. John. In addition to local Caribbean White and Yellow varieties, Nate grows Ma’afala which he distributes to farms, home owners, and government properties in order to improve food security and local economic development.

Breadfruit was introduced to the Caribbean in the 1790s and has long been used in traditional dishes like callaloo, tostones, and monfongo. Although breadfruit is considered a local crop, Nate says, “We’re very respectful of the food and its identity…we feel connected with our brothers and sisters in the Pacific.”

breadfruit
Barney Gibbs teaches cub scouts on Barbados about using breadfruit for ‘fruitscaping’ on a pubic trail. Photo by Andrew Clarke

Breadfruit for all

Five hundred miles southeast of St. Croix, on the island nation of Barbados, breadfruit is eaten with flying fish as a mash called coucou. Barney Gibbs, chairman for the Future Centre Trust, one of Barbados’s oldest environmental NGOs partners with Trees That Feed to provide for urban reforestation. Barney says importing breadfruit has allowed him to introduce greater horticultural variety to the island.

Since 2015, Barney has received three shipments of around one thousand Ma’afala which, he says, has proven to be popular for its compact, easy-to-manage. He adds that the pandemic has only made breadfruit more popular as a nutritious, reliable crop, and for use in value-added products like flour, chips, and other foods.

Barney’s main project is urban reforestation along a nineteenth-century railway line that was converted into a biking and walking trail. The Barbados Trailway project is being lined with breadfruit and other fruit-bearing trees, providing food for anyone who needs it. Other trees are given to local schools and community centers.

breadfruit
Nganga and Ivy (yellow Shirt) care for a young breadfruit tree on a farm in Mombasa, Kenya. Photo by Mary Kibai

New to Africa

Meanwhile, across the Atlantic, Catholic nuns in Kenya are harvesting what they call in Swahili shelisheli (breadfruit). Unlike in the Caribbean, breadfruit is a recent introduction. Joseph Matara, founder and executive director of the non-profit Grace Project (and Trees That Feed board member) welcomes the new crop. Joseph works closely with Mary and Mike to ship Otea and Ma’afala trees to Mombasa, Kenya, Dar es Salaam, Tanzania, and Uganda’s Jinja district, north of Lake Victoria.

Like a handful of breadfruit trees believed to have been imported to Zanzibar from Goa long ago, breadfruit is proving to be best suited along East Africa’s coastal regions. Joseph has coordinated the donation of young trees to schools and other places where they are most needed. The high nutritional value and versatility of breadfruit make it ideal for improving food security. “For some of these children,” Joseph says, “what they eat at school is their only meal for the day.”

Other projects in West Africa (Ghana and Liberia) are taking root and Joseph sees great potential for breadfruit in Mozambique too.

Saving Lives in Haiti  

At its core, the Trees That Feed Foundation is about helping people. Mary recalls shipping one thousand breadfruit trees to Haiti in July 2021. Those trees arrived less than 24 hours before Haiti’s president was assassinated, an event that led to great instability. One month later, Haiti was rocked by a 7.2 earthquake and powerful tropical storm which soaked the nation already upended by political violence, poverty, and COVID.

Mary says that after last summer’s earthquake, trees they had imported in 2012 proved to be a lifesaver when other food sources were cut off. “The work of NTBG helped us get established to where we could feed thousands of people in the area immediately around the epicenter of the earthquake.”

Mike adds the network between the Breadfruit Institute, Trees That Feed, and other partners is a testament to the power of breadfruit. “We are ecstatic about being able to collaborate with NTBG. We couldn’t do what we’ve done if they hadn’t helped us so much.”

Mary too says she’s grateful for the partnership. “If breadfruit can be the source of a job, an environmental benefit, and feed the world’s poorest people, then I think we’ve done a pretty damn good job.”

How a Garden Can Save a Stream

Restoration efforts in Limahuli Valley show how a garden can save a stream.

by Dr. Uma Nagendra, Conservation Operations Manager, Limahuli Garden and Preserve with Puakea Moʻokini-Oliveira, Conservation Technician

In the middle of Limahuli Stream, cold mountain water cascades down boulders into a hip-deep pool. I am grateful for the wetsuit keeping me warm. Small river stones slick with algae slip beneath my tabis (water shoes). If I stay still, I might feel the dull pinch of Tahitian prawns nibbling my toes. Looking up at Limahuli Valley, I can see both sides of the cliffs where koae (white-tailed tropic birds) dart into their nests. I don my snorkel mask, nod to lead technician Puakea Moʻokini-Oliveira, who is standing on the bank with a timer and waterproof datasheets, take a deep breath, and dunk myself into the frigid water to enter the aquatic world of freshwater fishes. 

Immediately, several oopu nakea[1] dart away along the stream bottom, leaving silty clouds in their wake. As I step in their direction, I can see an oopu alamoo resting on a dark stone, its bright orange tail curled slightly against the rock contours. I almost miss the crowd of oopu nopili grazing on a patch of green algae because they are so close to the waterfall cascade. 

How a Garden Can Save a Stream
Puakea Mookini-oliveira snorkeling in the Lumahuli stream to gather data. Photo by Kassandra Jensen.

This underwater survey is a component of The Haʻena ʻOʻopu Restoration Project, a two-year project funded by the Hawaii Fish Habitat Partnership in order to enhance stream health and oopu population numbers in Limahuli Stream. Freshwater aquatic species like oopu were once a major food source, although now few Hawaii residents have ever seen one. 

While this underwater world may feel completely removed from the terrestrial world we inhabit at NTBG, they are actually intricately intertwined. Limahuli Stream is the thread connecting all parts of the watershed from mauka to makai (mountains to the sea). From the mist caught by the ohia (Metrosideros sp.) canopy in the uppermost valley, filtered down through moss, leaf litter and soil, flowing underground through porous rock, or overland in rivulets and gulches, all the valley’s water eventually follows Limahuli Stream to the ocean.

“In Many ways, the health of the stream indictes the health of the rest of the valley.”

Dr. Uma Nagendra, Conservation Operations Manager

Streams carry carbon, nutrients, and silt to the reef. Riparian ecosystems (streams and stream banks) offer unique habitats for plants and animals that are adapted to constantly moist, periodically flooded conditions. In many ways, the health of the stream indicates the health of the rest of the valley. Healthy streams also provide critical ecosystem services such as clean water, erosion prevention, and food.

With the abandonment of traditional stream management practices and introduction of invasive species, stream health has declined throughout Hawaii. Stream diversions, blockages, and invasive species overgrowth have adversely transformed many riparian systems that were once highly productive and biodiverse ecosystems.

Although Limahuli Stream is considered “pristine,” with high levels of biodiversity and among the least disturbed stream systems on Kauai, it is home to far fewer oopu than neighboring Hanakapiai Stream. A past comparison of the two suggests that the amount of sunlight reaching the streams could be a major contributing factor to the lower population in Limahuli. Native green algae are the foundation of the riparian food web, and thrive in high light conditions. A promising pilot study led by NTBG research associate Kawika Winter[2] several decades ago tested this idea on a small scale. The Hāʻena ʻOʻopu Restoration Project expanded that study in order to see if opening up longer sunny stream corridors (as would have been maintained with traditional stream management) would also increase green algae growth and oopu populations. 

One of the main activities of this project was the selective trimming of Schefflera actinophylla, a highly-invasive tree species that threatens the health and resilience of the riparian ecosystem by preventing sunlight from reaching the stream, which limits green algae growth. The tree’s high evapotranspiration rates and inhibition of understory growth reduce groundwater penetration and storage, contributing to flash floods and erosion. Schefflera’s sprawling growth forms also threaten the integrity of valuable cultural resources. For this project, invasive trees were trimmed by an experienced local arborist crew (Haleleʻa Tree Service), with the help of Limahuli Garden staff. 

How a Garden Can Save a Stream
NTBG staff and volunteers carry native plants used as part of the Haena oopu restoration project. Photo by Uma Nagendra

Afterwards, Puakea and I started planting on the freshly cleared stream banks, with the help of many other Limahuli staff, KUPU service members, and volunteers. We hand-carried and planted over 4,742 native plants like kokio keokeo (Hibiscus waimeae hannerae), hala (Pandanus tectorius), and many others[3].

How a Garden Can Save a Stream
Native Hawaiian plants used in the restoration project. Photos by Uma Nagendra.

The mix of species was selected in consultation with previous restoration managers and living collections experts at NTBG. These included species sourced from northwest Kauai, quick to establish and grow in riparian areas, and which have strong root systems that will help prevent future erosion on a now-vulnerable stream bank. We also chose a few species that are likely pollinated by moths (scented, white, night-blooming flowers) in order to further promote moth habitat, including endemic Hyposmocoma and the opeapea (Hawaiian hoary bat) that feeds on them. 

Throughout the project, Puakea conducted stream surveys to assess how the aquatic wildlife were responding to this change. The entire 1,500-foot restoration area was divided into three 500-foot sections where we swam for an underwater census of the aquatic animals. We also surveyed a cross-section of different parts of the stream to document the algal growth, substrate composition, and stream characteristics like water temperature, flow rate, and canopy openness. 

Setting up a stream cross-section transect to measure habitat changes. Photo by Kassandra Jensen.

Spending so much time along the stream banks allowed us to observe just how many other species enjoy this area as well. By investigating the lower stream, Puakea was able to note how hīhīwai[4] migrated up the stream into our restoration zone — and even spotted their small pink eggs on the rocks. While we planted or weeded, we were often joined by an aukuu (Black-crowned Night Heron) standing statue-like to fish on a nearby boulder, or a pair of Koloa maoli ducks playing in the current. 

One of the best parts of this project was working with school groups, volunteers, and partnering community organizations. Although COVID precautions limited our interactions after the first six months of the project, we were able to welcome two recurring classes from Kanuikapono Public Charter School, a work-exchange with the Waipā Foundation, and a new stream research collaboration led by the non-profit Nā Maka Onaona. 

Our results indicated that canopy openness alone was not enough to boost oopu population numbers within the time frame of this project. Aquatic animal diversity remained high, however, and indicators of stream health such as temperature were unchanged. By restoring the stream banks to native habitat, the stream corridor should now be even more hospitable to native birds, bats, and invertebrates, and safer from the invasive tree falls that exacerbated flood impacts in 2018.

The completion of this project is just the start of this important new restoration area. In order to sustain those benefits, we will need to continue maintaining the stream corridor. Ongoing collaborative stream monitoring will also help improve our understanding of watershed resilience both in the Limahuli Valley and in freshwater systems all across Hawaii. 

Editor’s note: The author wishes to thank those who contributed significantly to this project: Kawika Winter, Ashley Ramelb, Saori Umetsu, Moku Chandler, Noah Kaaumoana, Pelika Andrade, Mackenzie Fugett, Lauren Pederson, Matthew Kahokuloa Jr., Kassandra Jensen, Joshua Diem, Emma Stauber, and others. Funding for this project was provided by The Hawaii Fish Habitat Partnership, which is coordinated by the U.S. Fish and Wildlife Service.


[1] ʻOʻopu are species (Awaous sp.) of goby native to Hawaii. The three most common ʻoʻopu in Limahuli stream are ʻoʻopu nākea (Awaous guamensisi), ʻoʻopu alamoʻo (Lentipes concolor), and ʻoʻopu nōpili (Sicyopterus stimpsoni)

[2] Dr. Kawika Winter was director of Limahuli Garden and Preserve from 2005 to 2018.

[3] Including koaia (Acacia koaia), māmaki (Pipturus kauaiensis), ʻākia (Wikstroemia oahuensis), koʻokoʻolau (Bidens forbesii forbesii), and ground covers such as ahuʻawa (Cyperus javanicus), makaloa (Cyperus laevigatus), pili (Heteropogon contortus) and ʻaeʻae (Bacopa monnieri). 

[4] Endemic freshwater snail (Neritina granosa)

Hawaii Education Series

Plants are the basis of healthy ecosystems from ridge to reef across Hawaii. The islands have truly unique and diverse ecosystems that provide our communities with a myriad of critical resources.

NTBG’s Hawaii Education Series provides students and families with fun and inspirational videos and activities exploring the plants, cultural resources, and people that make Hawaii special. Explore the videos below and check out more resources on our education page.

Hawaii Education Series: Ferns

Ferns are among the oldest living plants on the planet and play many important roles in their ecosystems, especially in Hawaii. Check out this video to get a quick overview of ferns in their natural environment, fern anatomy, fern lab propagation, and a fun experiment to do at home or in the classroom!

Hawaii Education Series: Canoe Plants

The landscape of Hawaii is filled with what we refer to as ‘canoe plants.’ These plants might even be growing in your school playground! So, what is a canoe plant? Canoe plants were brought to the Hawaiian Islands by our ancestors, the Polynesian voyagers. Check out this video to get a quick overview of canoe plants and a how-to on making a Ti (Ki) leaf lei.

Hawaii Education Series: Ahupua’a

Learn about traditional Hawaiian land management systems (Ahupua’a) through a virtual visit to NTBG’s Limahuli Garden and Preserve. Humans have inhabited and cared for Limahuli valley for over a thousand years. It is home to many of our native plants and animals like our native ʻaʻo, moths, ‘o’opu, laua’e ferns, papala trees, and so much more.

5 Reasons to Plant Native Plants

All native plants in peoples’ home landscape help preserve biodiversity. This is important for the future conservation of native species. Want to be a good neighbor to Hawaii’s native flora? Learn more about gardening with native plants at ntbg.org/gardening and do your part to save plants today.

Saving Spores

Often overlooked, ferns are a critical part of Hawaii’s native forest ecosystems and watersheds. Since 2007, the NTBG Fern Laboratory has been one of very few botanical research centers focused on the study and propagation of rare Hawaiian Ferns, which make up nearly 27.4 percent, or more than a quarter, of native flora. The need to understand and protect these vital species has never been greater. Read on to learn more about the Fern Lab, NTBG research, and how you can help save species today.  

Hawai’i: Land of Pteridophytes

When you picture the flora of the Hawaiian Islands, colorful hibiscus, sweetly scented plumeria, and swaying coconut palms may be the first to come to mind. While important, these plants commonly associated with Hawaii are vastly outnumbered in native ecosystems by ferns. Across the islands, ferns dominate many niches in the wet, dry, and mesic forest environments. They absorb heavy rains, mitigate runoff, and provide habitat for native birds, moths, snails, and insects. Altogether there are 159 native species of ferns and lycophytes in the Hawaiian Islands, with 74 percent of those endemic to the islands. 

The abundance and variety of ferns in Hawai’i are extraordinary, but so are the threats they face. Like many native Hawaiian plants, ferns are threatened by other plants, animals, disease, and loss of habitat. Ferns are particularly vulnerable because they lack defenses and usually grow low to the ground, near the mouths of hungry pigs, goats, and deer.

saving spores
Asplenium aethiopicum

Saving Spores, Saving Ferns

Critically endangered Hawaiian ferns have been at the center of NTBG Research Associate, Dr. Ruth Aguraiuja’s work for more than two decades. Previously, as a senior researcher at Tallinna Botaanikaaed (Tallinn Botanic Garden) in Estonia, Dr. Aguraiuja’s desire to learn more about Hawaiian fern biology, ecology, and conservation methods has led to many breakthroughs as well as the reintroduction of hundreds of plants to their in situ habitat on Kauai. 

Finding efficient propagation and conservation methods is critical to success because growing some native ferns can be time-consuming. In 2016, Dr. Aguraiuja shuttled hundreds of native Hawaiian Asplenium ferns propagated from spores in Estonia back to Kauai. Dr. Aguraiuja collected the spores in 2011 while botanizing in the high elevation forests of Kaua’i. In their early stages, ferns can grow very, very slowly, sometimes taking as long as two years to become a sporophyte and develop simple, tiny fronds. Thanks to Dr. Aguraiuja’s work and partnership, NTBG, staff, researchers, and interns have continued to utilize the Fern Lab to propagate rare, endangered, and culturally significant ferns from tiny spores, and to preserve genetic diversity needed to re-establish endangered populations in the wild. 

Prior to the existence of the Fern Lab, propagation was primarily done through division (splitting of one plant into two or more by breaking the original in half with roots and crown attached to both halves). While division is a successful and efficient method for species with long creeping and branching rhizome (underground horizontal stems), each new plant is an exact clone of the parent. This does not promote genetic diversity, a key component in successful restoration and species conservation. Additionally, not all ferns species can be propagated in this way. By developing the protocols to grow ferns successfully from spores, we will be able to maintain the genetic diversity found in nature, and we will broaden our list of species, particularly the rare ones, that we can conserve and add to both ex situ and in situ conservation sites. 

Today, spore propagation is taking center stage in the Fern Lab, but there is still much to discover about these hardworking Hawaiian plants. 

Fern Lab

Why Fund Fern Research?

Pristine areas of Hawai’i are covered in ferns, which makes them critically important to restoration and conservation efforts, but little research is happening on a large-enough scale to make a big impact now. “Ferns provide the foundation of functioning ecosystems in Hawaii and we still have so much to learn about them,” said Mike DeMotta, NTBG’s Curator of Living Collections. “For example, the time from propagation to outplanting varies across species. For some rare ferns it takes four years to go from gametophyte to plantlet. For others we can outplant within months to a year – this is why we need to support our Fern Lab, so we can learn how to best grow and care for our native species ex situ and in the wild.”

Providing additional support to the NTBG Fern Lab will go further than propagation and outplanting. It will also provide bandwidth for further study and continuity not previously available. “I am excited about the potential of what we can learn and do with full-time staff and funding in the Fern Lab,” said Mr. DeMotta. 

In addition to the propagation of ferns, NTBG interns are currently looking at fern spores saved in the herbarium collection and conducting propagation studies to see if spores retain their viability after drying. When possible, fresh spores of the same species are collected and propagated in the Fern Lab and compared to the dried spores. “Our hope with this study is to be able to recover more fern species from dried collections that have become rare over time”, noted Mr. DeMotta. 

The Need is Upon Us

Hawai’i is a biodiversity hotspot which means the islands, while biologically diverse, also suffer from a high rate of habitat and species loss. In other words, the need for enhanced support directed toward the conservation of floristic diversity in Hawaii and tropical regions around the world is great. 

“We need a renaissance in conservation,” said Ken Wood, NTBG Senior Research Biologist. “Managing just one species requires so much support. To manage and restore entire ecosystems of threatened and endangered plants requires action today. Now is the time to spread the word. Get your friends, family, and organizations involved,” Mr. Wood continued. 

NTBG is dedicated to tropical plant discovery, conservation and research. Our work includes conducting regional plant surveys, documenting and describing new species, publishing data, furthering conservation efforts through research, protection, and cultivation, and re-establishing populations of rare plant taxa in situ

Funding the Fern Lab and protecting native ferns is just one of the ways we are saving plants and saving people. You can support these critical and comprehensive efforts to protect plants and tropical ecosystems worldwide with a gift today. Donate now

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