Tree of the Week: October 29th, 2024

ArborNote’s Tree of the Week is the Māmane Tree (Sophora chrysophylla). This tree is endemic to the Hawaii islands, meaning that it is only native to that island chain. It likes higher altitude and most commonly grows between 4,000 to 8,000 feet. Its beautiful golden-yellow flowers bloom in the winter and spring. The seedpods remain year-round, and are extremely important to the endangered Palila (Loxioides bailleui), which feeds almost exclusively on the plant’s seeds, and uses the branches to create its nests. However, to other animals, māmane seeds are highly poisonous. House finches die within minutes after eating the seeds! The seeds contain deadly levels of quinolizidine alkaloids, like Cytisine, that can be fatal to many animals. The Palila, however, have evolved the ability to deal with the poisonous compounds through years of evolution. The Palila can deal with dozens of times the dose of cytisine that would kill a laboratory mouse! The Palila is highly endangered, so there has been a big push to conserve the Māmane Tree to help the Palila repopulate. The Hawaiian islands have been planting more Māmane Trees and fencing off and restricting access to the groves that already exist to try and help the Palila thrive!