This article by Jodie Rosam was featured in The Kaʻū Calendar News Briefs on September 6th, 2021.

(Pahala, Hawaiʻi) — “Welcome to Lāʻau Letters: Native Plants of Kaʻū. Read about Kaʻū’s native plants and their 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.

Wiliwili (Erythrina sandwichensis)
Pua ka wiliwili nanahu ka manō
(When the wiliwili tree blooms, the sharks bite) –ʻŌlelo Noʻeau by Mary Kawena Pukui

Description: Wiliwili is an endemic tree in the pea family (Fabaceae), and much like last month’s featured lāʻau ʻohe makai, it is drought-deciduous (it drops its leaves during the dry season). The showy orange, red, salmon, peach, light green, yellow, or even white flowers bloom during the summer months after the leaves drop, and the nearly heart-shaped leaflets emerge in threes during the fall. Wiliwili can grow quite large, exceeding 45 feet tall with an impressively wide crown. Wili means to twist, screw, or wind, and wiliwili means repeatedly twisted, referring to the seed pods that twist to expose the bright, coral colored seeds. Did you know wiliwili were on the brink of extinction in 2005 when an infestation of the Erythrina Gall Wasp (EGW) began killing a number of trees? Fortunately, the release of the Eurytoma parasitoid wasp as a biocontrol in 2008 successfully and significantly reduced the EWG and saved our wiliwili!

Uses: Because of its low density, the wood of wiliwili was used for ama (outrigger canoe floats) and mouo (fishing floats). Most notably, wiliwili wood was the preferred choice for papa heʻe nalu (surfboards), specifically for olo, or longboards, which were ridden by the aliʻi. The shiny orange and red seeds are still used in lei.

Habitat: Wiliwili grow in harsh environments including barren lava flows and dry forests up to 1,950 feet elevation. Waikōloa is known for its large wiliwili population, but Kaʻū is arguably home to just as many! Look for the brightly colored flowers across the lowland dry forests makai of Waiʻōhinu during the summer (now!). Three wiliwili sisters formerly guarded Puhiʻula Cave at Pāʻula (Kaunāmano Ahupuaʻa), and are still alive in moʻolelo (stories) shared today.

Growing and Purchasing: Seeds must be scarified (I use nail clippers to knick the seed coat on the opposite side of the seed’s piko) and soaked for 12-24 hours to increase germination success. Pot soaked seeds in a well-drained mix (cinder soil mixes), and fertilize regularly until they are planted (because fix Nitrogen, no additional fertilizer is required once they are in the ground). Be sure to choose a sunny area for your drought, heat, and wind tolerant wiliwili to thrive. Plants may be available for purchase through Future Forests, or contact the author.

Mahalo to Jodie Rosam with Pūlama Mau Environmental Consulting (and part-time HWF team member) and Julia Neal with The Kaʻū Calendar for allowing us to share this story!

Photos of the contributors, Joan (left) and Jodie (right) –>