‘Uala is a type of sweet potato that was and remains a staple of the local diet. In ancient times, the Hawaiians recognized some 230 varieties of this plant, although only about 24 are known today. The ones growing here are probably the variety piko.

The vine, started from slips, grows very fast during the wet season but is drought tolerant and produces numerous underground tubers harvested for food. The crop was a particularly important staple in drier areas where kalo could not be grown. For cropping purposes, ‘uala is often grown in low mounds or ridges called pu‘e and an ‘uala pu‘e garden is growing on the north side of the park. The leaves are also eaten.

The tuber has a purple skin and moist yellow or orange interior flesh. These are NOT yams; a yam, has a rough, dark skin and dry, more white flesh, although this can vary. Yams are a staple in West Africa. More often seen in Hawai‘i in modern times is the Okinawan sweet potato with a tan skin and purple flesh.