There were over fourty different varieties of ko or known as sugar cane. Ko was used for only three things.
The stem of the sugar cane was chewed las a sweet candy because like the name, it was made out of sugar!! In the olden days (and probably some still going on) people used sugar can to produce sugar. Travelers would eat it on long journeys, and it was chewed for quick energy. The juice of the cane was used to feed babies and it was to sweeten deserts like kulolo (a coconut cream pudding), haupia, and kalo.
Like the food, I said ko was used to sweeten food. Well, it also sweetens the medicines or it was chewed after taking the medicine so it wouldn't taste all that bad.
Usually pili grass, a long type of grass, was used to thatch houses or cover walls. If the pili grass was scarce, ko would be used in place of the pili.