HAWAII NATURE NOTES
THE PUBLICATION OF THE
NATURALIST DIVISION, HAWAII NATIONAL PARK
AND THE HAWAII NATURAL HISTORY ASSOCIATION

AMAUMAU AND AMAU

The most abundant ferns growing beneath the larger tree ferns are AMAUMAU (40) and the AMAU (41). Found frequently in both the Kilauea and Haleakala sections of the Park, the amaumau is usually larger than the less common amau and the fronds are not as hairy. The easiest method of identification, however, is by comparing the undersides of the frond segments (see illustration). The amaumau is smooth while the amau is prominently veined. Usually smaller than the true tree ferns, and known only from the Hawaiian Islands, ferns of this genus may reach heights as great as 12 feet. A comparison of the photographs of these ferns with the tree ferns will show that the entire frond of the AMAU or AMAUMAU resembles a single segment of the many-branched frond of the tree fern.

The AMAUMAU fern has a high resistance to heat and drought, and may often be seen growing on the Kau Desert near Kilauea crater. It is one of the first plants to take root on new lava flows, in company with the ohia tree. The illustration below shows a specimen growing on the 1877 lava which forms the floor of Keanakokoi crater.

Fowler (4, p. 16) states that the Hawaiians prepared a red dye used on KAPA cloth from the outer part of the trunk of the amaumau. Leaves of the amau provided a lining and thatching for houses, and the young leaves and pith of the stems were occasionally cooked for food.