This article by Jodie Rosam was featured in The Kaʻū Calendar News Briefs on November 13th, 2023.
(Pahala, Hawaiʻi) — Welcome to Lāʻau Letters: Native Plants of Kaʻū. Read about Kaʻū’s native plants’ moʻolelo (stories), uses, preferred habitats, and opportunities to adopt them for stewardship. This column seeks to encourage making new plant friends and to reunite with others.
Kupukupu (Nephrolepis exaltata subsp. hawaiiensis)
Kupukupu, Nephrolepis exaltata subsp. hawaiiensis, is one of Hawaiʻi’s endemic sword ferns and is featured in the monthly column Lāʻau Letters: Native Plants of Kaʻū. This artwork is shared courtesy of Joan Yoshioka.
Description: Kupukupu, or sometimes called ʻōkupuku or niʻaniʻau, is an endemic sword fern, with two native Nephrolepis species found in Hawaiʻi: N. cordifolia (either considered an indigenous species or an early Polynesian introduction), and N. exaltata subsp. Hawaiiensis (an endemic species). Unfortunately, both native species hybridize regularly with the non-native (and also invasive) N. multiflora, which is contributing to the loss of genetic integrity in this species. Kupukupu fronds stand erectly about 1-2 feet tall and have a width of 2-3 inches, and are composed of smaller pinnae (frondlets). The stolons (sprawling stems which look a lot like roots) can spread across the ground and also climb up trees. A defining characteristic of this species is that it has underground tubers (or underground organs, similar to kalo corm) that not only store food and nutrients, but also generate new fern babies.
Although the weather has been quite hot, we are in the time of Makahiki, as we transition from the season of Kau (summer, represented by Kū) into the season of Hoʻoilo (winter, represented by Lono). Kupukupu is a great symbolism of both the upright and tall nature of Kū and the wide and sprawling nature of Lono. Representing growth, kupukupu also is consistent with this change of seasons as we enter into a time of abundance. Perhaps you can sit with kupukupu for some time and notice any symbolism it offers to you.
Uses: Kupu means “to sprout”, and kupukupu are often used to decorate hula kuahu (altars), symbolizing sprouting knowledge. Fronds are also a common component of kūpeʻe (lei for wrists and ankles) and lei poʻo (for the head). Medicinally, the pressed juice is great for the skin and can be used as a remedy for multiple skin disorders. Kupukupu has a delicate scent that accompanies its beauty in adornment.
Habitat: Kupukupu is a relatively common forest friend, growing on all of the main islands except for Kahoʻolawe. It can occupy sites between 100 and 4,600 feet elevation in mesic, wet, and even upper elevation dryland forests. In Kaʻū, there are Nephrolepis fern species all around – roadside, planters, even growing epiphytically in the trees. Unfortunately, what we see more commonly is a non-native or hybridized Nephrolepis. True kupukupu are restricted to more protected forest reserves and a little more difficult to come by.
Growing and Purchasing: Kupukupu are often sold at nurseries, and are relatively easy to propagate, as they produce shoots that will quickly develop and spread into full-sized reproducing plants themselves. They make a great container plant and landscaping component, groundcover, and can even be planted at the bases of rock walls (where they will slowly climb up). When you plant your kupukupu, give them room – these ferns like to grow and will out-compete one another. While they can survive full sun, kupukupu really likes to keep cool, so offer them a space with at least partial shade. Do you have other native trees on your property? Pop some kupukupu at the base of their trunks! Soon your kupukupu will begin to spread and sprawl (hmmm, Lono imagery again) and you will be able to share it with friends and family. Lonoikamakahiki!
About the Author, Jodie Rosam: A Ka’ū resident, Jodie Rosam, says she has a deep love for native plants and a passion for exploration, with over 15 years experience working in restoring Hawai’i forests. She is the Kaʻū representative on the County’s Public Access, Open Space, and Natural Resource Preservation Commission (PONC) and sits on many other non-profit boards. Jodie enjoys sharing her love of plants with everyone – plant love is contagious!
About the Artist, Joan Yoshioka: A Volcano resident, Joan Yoshioka, is a conservationist at heart and has dedicated her life to preserving the native plants and animals of Hawai’i through her work with federal, state, and private organizations for more than 30 years. She said the key to the most fundamental and truest part of ourselves is found in nature and she constantly draws on it for inspiration.
