Flower Back from the Brink of Extinction in Haleakalā National Park
During the summer of 2020, the National Park Service and Hawai’i Department of Forestry and Wildlife successfully planted 141 critically endangered ‘ōhā wai (Hana Clermontia, Clermontia samuelii ssp. Samuelii) into one of the wettest rainforests in the world.
Saving the ‘ōhā wai from extinction required park staff to gather cuttings and seeds from wild populations, raise plants in a nursery, fly into remote areas on the eastern slope of Haleakalā, and hike across challenging terrain into dense rainforest.
Reaching up to 15 feet high, ‘ōhā wai are large shrubs with beautiful curved purple flowers that produce nectar and pollen. ‘Ōhā wai populations once thrived in the lush rainforests of East Maui. Now, with fewer than 50 plants left on the eastern slopes of Haleakalā, the ‘ōhā wai is one of the world’s most endangered plants.
‘Ōhā wai are pollinated exclusively by the large bills of the nectar-feeding Hawaiian honeycreepers. Unfortunately, many of the Hawaiian Honeycreepers are now extinct and the plant depends on the i’iwi (scarlet honeycreeper) for reproduction. The introduction of rats, pigs and slugs has accelerated the decline of ‘ōhā wai populations. Rats and slugs gnaw the bark and eat the seeds while feral pigs uproot and destroy their seedlings.
With so few plants left, there was an urgent need for NPS to take action. ‘Ōhā wai cuttings and seeds were collected in the wild and grown in the Haleakalā National Park nursery, which contains a wide variety of endemic and native species. There are only 10 known genetically different ‘ōhā wai populations left in the wild and 9 of these populations are represented in the nursery. NPS Horticulturalist Michelle Osgood, described the multi-year process, “To maximize genetic diversity, maternal plant lineages are tracked before the plants are outplanted. This summer we were excited to locate a healthy ‘ōhā wai plant that hadn’t been seen in the wild for over 20 years! Each individual plant we find is critical for the population’s genetic diversity.”
After plants in the nursery are mature enough to outplant, biologists face the challenge of accessing the remote, rainy and difficult planting locations by helicopter. ‘Ōhā wai populations are typically found at elevations of 5,495 feet to 7,000 feet on the windward side of East Maui where up to 420 inches of rain each year. Since 2015, a total of 286 ‘ōhā wai plants have been outplanted into the wild.