Native Plant Highlight: Māmane

April is native Hawaiian plant month. In light of this momentous month, the plant for this native plant highlight is Māmane, Sophora chrysophylla. 

Plant Description 

Māmane is an endemic plant that grows as a low shrub, all the way up to a 50-foot-tall tree.

Māmane Flower and Leaves, Mauna Kea - Credit: Kai Garcia-Tobar

Though it was once common in most dry areas in Hawai’i, māmane is now mostly restricted to high elevation forests, between 5,800 and 10,000 feet. Māmane leaves are dark green to silvery green and consist of pairs of 6 to 10 oval leaflets. Māmane flowers en masse in spring and winter, and trees can be seen covered in yellow blossoms. The flowers are followed by seed pods that mature to be hard and woody, reaching 6 inches in length.

Scientific Roots

Māmane is in the pea family, Fabaceae, and shares common characteristics with many other members of the family. Like many other species, māmane flowers are similarly shaped to pea flowers. Also, like other species in the family, māmane is a nitrogen fixer. Species in the genus Sophora have a pantropical distribution and can be found in New Zealand, Polynesia, Asia, and the Americas. 

Palila, Mauna Kea - Credit:https://hawaiibirdingtrails.hawaii.gov/bird/palila/https://hawaiibirdingtrails.hawaii.gov/bird/palila/

Old Trees, Pu'u Wa'awa'a - Credit: Kai Garcia-Tobar

Cultural Significance

Māmane held significant value in ancient Hawaiian culture, and ancient Hawaiians had many uses for it. Its flowers were used as an astringent and to make lei, and its durable wood was used to construct houses, farming spades, firewood, and scraping boards. Additionally, its wood was used to make papa hōlua for land-sledding. 

Threats

Māmane’s biggest threats stem from land clearing for agricultural development, and browsing from invasive ruminants like goats and sheep. It is said that in the past, from Hilo, it would appear that Mauna Kea was adorned in a yellow lei when the māmane trees bloomed en masse. Historically, māmane would have been seen in elevations as low as 1,400 feet and possibly lower, but it is now largely restricted to subalpine environments because of these human-caused pressures. Māmane is also threatened by bushfires. Māmane’s drastic reduction in range has been the biggest threat to Palila populations. 

Credit: https://dlnr.hawaii.gov/restoremaunakea/management/palila-management/

Māmane forests face constant threats from human actions and invasive ruminants. Luckily, organizations like Mauna Kea Forest Restoration Project work hard to preserve old māmane forests and plant new ones. If you would like to be involved, MKFRP hosts volunteer days, which can be found here: (https://dlnr.hawaii.gov/restoremaunakea/how-you-can-help/). 

Māmane is an ecologically and culturally important tree. It’s our duty to protect and restore its historic range and reverse the damage we humans have caused.