Amy Tsuneyoshi
Hawai‘i Herald Columnist

Yellow ‘Ōhi‘a tree in the forest. (Photos by Amy Tsuneyoshi)
Yellow ‘Ōhi‘a tree in the forest. (Photos by Amy Tsuneyoshi)

Arbor day in Hawai‘i is celebrated on the first Saturday in November. This year there are various events planned throughout the month, and on Saturday, Nov. 18, there will be ‘Ōhi‘a Love Fest events on O‘ahu, Hawai‘i and Kaua‘i to celebrate our iconic Hawaiian tree, ‘Ōhi‘a Lehua.

Did you know that on May 24, 2022, Gov. Ige signed SB2059 into law designating ‘Ōhi‘a Lehua as the official Hawai‘i State Endemic Tree? This is in addition to the official state tree- Kukui (Aleurites mollucana), which is actually a Polynesian introduced plant.

Endemic? Polynesian introduced? What does this mean? These are terms used to distinguish species that inhabited these islands before human contact versus plants people brought to Hawai‘i. Native plants traveled thousands of miles, landed on these tiny specks of land in the vast ocean and developed into forests all on their own. Seeds and spores hitched a ride in or on birds, wind and ocean currents otherwise referred to as the 3 W’s- Wings (birds), Wind, and Waves (ocean). Over thousands of generations, some native plants changed to better adapt to their new environment and became new species (endemic), while other native plants remained the same (indigenous). When the first settlers landed in Hawai‘i, they brought plants they needed to sustain them during the long voyage as well as to plant once they reached their new home. These are canoe plants or Polynesian introduced plants.

‘Ōhi‘a (Metrosideros polymorpha) is a native endemic plant that is one of the most common native trees in our forest and can be found in many different elevations and habitats. It is one of the pioneer species to sprout in areas covered by lava flows and is one of the dominant canopy trees in our rain forests that help to capture rain, fog and cloud moisture to help recharge our groundwater aquifers. The plant is culturally significant and is associated with hula and various deities like Pele, Laka and Kü, and mentioned in stories, songs, and chants.

Red ‘Ōhi‘a flower.
Red ‘Ōhi‘a flower.

‘Ōhi‘a has a variety of growth habits ranging from low growing shrubs to towering canopy trees. Their leaves range in size, color and texture and their distinctive flowers range in color from pale orange to yellow to blood red. After the flowers are pollinated, it forms a cluster of seed capsules that pop open to reveal tiny dust-like seeds that are easily scattered by the wind. All parts of the plant can be used. Leaves, flowers and seed pods are used for lei, and the wood used for tools and implements. The flowers produce nectar that is an important food source for our native birds.

Unfortunately, there is a fungal disease that has been killing these iconic trees called Ceratocystis, otherwise known as Rapid ‘Ōhi‘a Death (ROD).

There are 5 things you can do to help prevent the spread of ROD:

  1. Avoid injuring ‘Ōhi‘a. Wounds create an entry for the fungus to infect the plant.
  2. Don’t transport ‘Ōhi‘a inter-island. There is a quarantine rule in place to help prevent the spread of ROD.
  3. Don’t move ‘Ōhi‘a wood.
  4. Clean your gear and tools. Rinse/brush to remove dirt and spray with 70% rubbing alcohol (shoes, hats, backpack).
  5. Wash your vehicle (tires/undercarriage) with detergent to remove soil/mud after visiting ROD infected areas or after driving off-road.

To learn more about ‘Ōhi‘a and ROD, please check out the ‘Ōhi‘a Love Fest events near you and visit their website listed in the Resources below.

Mahalo, it was a pleasure writing this monthly column. Now, it’s time to go outside and plant a tree!

Resources:

DLNR Press release announcing Hawai‘i’s state endemic tree: dlnr.hawaii.gov/blog/2022/05/24/nr22-071

‘Öhi‘a Love Fest: cms.ctahr.hawaii.edu/rod/EDUCATION-OUTREACH/‘ÖHI‘A-LOVE-FEST

Rapid ‘Öhi‘a Death: cms.ctahr.hawaii.edu/rod

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