Pulu in Wikipedia
Pulu is a silky material obtained from the fibers of the hapuʻu pulu (Cibotium glaucum), a tree fern of Hawaii. It is made of the brown hairs that cover the young fiddlehead as it uncoils. For a period in the 1800s, pulu was collected, dried, and exported as pillow and mattress stuffing. A stone structure in Hawai'i Volcanoes National Park known as the Old Pulu Factory was a site for drying and packing pulu. However, the discovery that pulu breaks down and crumbles into dust after only a few years led to the demise of the industry. In addition, pulu was often collected by cutting down the slow-growing hapuʻu, an extremely unsustainable method.
In old Hawaiʻi, women used pulu for their menstrual cycle. When their time came around, they were somewhat isolated to a house called hale pe'a or menstrual house. Men were strongly discouraged to set foot on the grounds of the hale peʻa, for they would be executed. Hawaiians organized the hapuʻu fern into two genders; male and female. Distinguishing between the pair was fairly easy; males had the tough pulu, and females had the soft pulu. All soiled pulu was then buried around the hale peʻa[