New Bishop Museum Checklist Maps Past, Present, and Future of Hawaiʻi’s Native and Invasive Plants

# New Bishop Museum Checklist Maps Past, Present, and Future of Hawaiʻi's Native and Invasive Plants

The free, downloadable resource contains updated information on species found on each of the main Hawaiian Islands.

Honolulu, Hawaiʻi — Bishop Museum, the State of Hawaiʻi Museum of Natural and Cultural History, is offering its updated "Botany Checklist" to the public as a free downloadable resource. Compiled by Botany researchers and technicians from the Museum's Natural Sciences Department, the Checklist of native and naturalized vascular* plants in Hawaiʻi can be accessed as a PDF at PlantsOfHawaii.org.

*Naturalized species are those from other parts of the world that have successfully established and spread on their own in a new area, after being transported there by humans. Naturalized species include invasive species which cause ecological harm, but not all naturalized species are invasive. Species known only from cultivation are omitted from the Checklist.

**Vascular plants include most land plants such as ferns, flowers, trees, and grasses. Mosses, algae, lichens, liverworts, and fungi are not included in the Checklist.

The Checklist features up-to-date information on all 3,133 plants found from Hōlanikū (Kure Atoll) to the island of Hawai'i. The goal of the Checklist is to provide science-based information for naturalists, land managers, field biologists, scientists, and anyone who seeks to understand the biogeography of the Hawaiian islands. For each species, common names, nativity information, conservation statuses, and the list of islands it is known from is provided, all supported by citations.

This is the first ever-Checklist to have extirpation (local extinction) statuses at an island level — for example, a species which is still present on Kaua'i but is no longer known to live on O'ahu. The Museum found that an average of 60 native species are extirpated from each of the main Hawaiian islands, with Lāna'i being especially affected with 151 species which were historically known now having disappeared from the island.

Hawaiʻi's endemism rate — of plants unique to Hawaiʻi and found nowhere else — is 90%, among the highest in the world. Kauaʻi has the most endemic plants (567) followed by Maui (565), Oʻahu (514), Hawaiʻi (432), Molokaʻi (402), Lānaʻi (282), Niʻihau (50), Kahoʻolawe (43).

"While this high number of endemic plants makes Hawaiʻi a truly unique place, it also means many of these plants are highly vulnerable, as they have not adapted to current threats facing the Hawaiian landscape such as invasive species, human impact, and shifts in climate," said Miles K. Thomas, Bishop Museum botany research specialist. The Museum recorded 139 endemic plants that are now extinct or extinct in the wild, with hundreds more in danger of extinction.

"We're offering the Botany Checklist as a free resource to share our data with researchers and citizen scientists alike, with the ultimate goal of bringing more awareness to our islands' precious biodiversity," added Thomas. "As the so-called 'extinction capital of the world,' it's extremely alarming how many native species we lose every year."

The decline in native species is correlated with a rise in the number of non-native species, as non-native species now outnumber native species, with 55% of all plants in the Checklist being non-native. "New endemic species have been discovered at approximately 2.4 per year over the past 30 years, and are generally decelerating as we run out of new habitat to survey," said Kevin Faccenda, Bishop Museum invasive species program manager. "On the other hand, new, non-native, naturalized species have been discovered at 13.9 per year over the past 30 years and show no signs of decelerating."

"In short, this means that our flora is changing at an alarming rate, and is changing towards an alien-dominated landscape that threatens Hawaiʻi's endemic biodiversity, greatly impacting our natural and cultural history," said Thomas. "Native ecosystems provide us with immeasurable benefits such as food, fiber, and drinking water, in addition to their natural beauty."

The Checklist was created and is regularly updated under the Hawaiʻi Biological Survey, a Bishop Museum program established by the Hawaiʻi State Legislature in 1992 to maintain comprehensive records of Hawaiʻi's plants, animals, and fungi. The Checklist is updated based on the Museum's natural history collection, specifically Botany's Herbarium Pacificum, which holds the largest and most comprehensive collection of Hawaiian and tropical Pacific Island plant specimens in the world including over 157,000 from Hawaiʻi. Nearly every record in the Checklist has a specimen in the Herbarium, which allows the Botany staff to confirm identifications and other data.

For the plant species that are extinct, Bishop Museum's Herbarium Pacificum is one of the few places in the world where researchers can study preserved specimens and learn about the biology of these species. These herbarium specimens are also essential for confirming the identity of a species if it is rediscovered.

As the State of Hawaiʻi Museum of Natural and Cultural History, Bishop Museum serves as the trusted source for Hawaiʻi's official lists of plants and animals and where they are found across the islands. These records are based on verified specimens and decades of scientific research, and they are used by government agencies, researchers, and conservation groups statewide. By keeping these lists current, the Museum helps Hawaiʻi track what species are still here, what has been lost, and what is changing on the landscape

"We hope that our global community can use the Checklist to learn more about the plants of Hawaiʻi and the habitats they reside in," said Thomas. "The more we all learn about our ʻāina (land) and the living beings that reside on them, the more we can care for and preserve them for generations to come."

Notable Findings from the Nov. 2025 Checklist

• 68% of native species have inoa Hawai'i (Hawaiian names) recorded in the Checklist.
• Invasive species have been successfully eradicated from a full island 66 times.
• Grasses are the most diverse family in the Checklist but are largely non-native or invasive species.
• Lobeliods (including Hāhā, Koli'i, 'Ōhā wai, 'Ōlulu) are the most diverse native family with Cyanea being the largest endemic genus of plants in Hawaiʻi.

The public can download the Checklist at PlantsOfHawaii.org.

PlantsOfHawaii.org is Bishop Museum's public gateway to authoritative information on the plants of Hawaiʻi, bringing decades of scientific research directly to the community. The website provides up-to-date species lists, island-by-island distributions, and verified data drawn from the Museum's collections and researchers. Designed for everyone from students and teachers to land managers and scientists, the site makes Hawaiʻi's plant diversity accessible, searchable, and free to use.