This article by Jodie Rosam was featured in The Kaʻū Calendar News Briefs on April 6th, 2022.
(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.
ʻŌhai (Sesbania tomentosa)
ʻŌhai, Sesbania tomentosa, is one of Hawaiʻi’s endangered endemic coastal species and is featured in the monthly column Lāʻau Letters: Native Plants of Kaʻū. This artwork is shared courtesy of Joan Yoshioka.
Description: ʻŌhai is another one of Hawaiʻs’s endangered endemic species (like last month’s featured friend, hala pepe), and belongs to the Fabaceae family (a cousin to wiliwili and māmane). This lovely lāʻau is variable, growing as a sprawling ground cover or even an upright shrub. Similar to other Fabaceae, each ʻōhai leaf is made up of many small, oval-shaped leaflets which in some cases are covered in tiny silver hairs. This trait is called tomentose (note that the species name of ʻōhai makes a connection to its namesake), and it is an evolutionary adaptation to the intense sun and heat. On sunny days, these leaflet clusters smell like sweet tangerines. The flowers commonly form in pairs, and are most often a crimson red, scarlet, or salmon color, although a very unique Kaʻū population bloom a lovely pure pastel yellow.
Uses: The bright and showy flowers of ʻōhai were historically used to make a gorgeous lei, although that was when the plants were more abundant. Because ʻōhai is an endangered species, there are legal protections which restrict collection of plant material. With that said, if you are able to purchase ʻōhai and cultivate it, the flowers are okay to pick (if you can bring yourself to pluck them – they are such a beautiful sight on the plant when in bloom). In addition, ʻōhai leaves can be placed under your pillow before bedtime to induce the dreamscape and help open up the space of learning and receiving messages.
Habitat: ʻŌhai have the potential to inhabit coastal and lowland dry areas from sea level to 2,500 feet elevation, though local populations today tend to be restricted to undeveloped coastlines (and are under the constant threat of habitat loss, displacement by invasive species, and feral ungulate pressures). ʻŌhai have been successfully outplanted in the Waikōloa Dry Forest Preserve (go visit them!) and protected along the coastline within Hawaiʻi Volcanoes National Park. In Kaʻū, a wild population remains along the coast within the Kamāʻoa Puʻuʻeo Ahupuaʻa. This area is known for off-roading, which, if not done responsibly, can ultimately decimate Kaʻū’s beloved ʻōhai population.
Growing and Purchasing: Because ʻōhai are endangered, it is not pono to collect seeds or plant material from wild plants. However, some nurseries specializing in native species are able to obtain the necessary permits to grow and sell them. ʻŌhai are nitrogen-fixing plants (as are all Fabaceae), so planting them in the landscape will enrich the soil and benefit surrounding plants. They prefer full sun and well-drained substrates, and enjoy being planted with a bit of clean beach sand. ʻŌhai would undoubtedly make a gorgeous addition to any landscape, preferably planted with plenty of room to sprawl and near other native plant friends.
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.
