Klau, klau pueo, pai, bracken, or Hawaiian bracken fernDennstaedtiaceae (Bracken family)Subspecies is endemic to the Hawaiian Islands (All the main islands except Niihau and Kahoolawe)Aiea Loop Trail, OahuBracken has been used throughout in many cultures around the world. The fiddlehead (immature unfurled fronds) are bitter, but used fresh, cooked, or preserved by pickling, salting, or sun drying. For example, in Korea, called gosari, they are used in bibimbap or gosari-namul, a sauteed side dish; and as a vegetable dish in Japan, called wasari.Native Americans pound the rhizomes in making a stachy flour for bread; and in Japan used a starch to make confections.In Hawaii, klau is collected and use in wasari. But "because bracken fern has cancerous properties and a nerve poison, it should be eaten infrequently and in moderation."A substitute for bracken, is the Vegetable fern (Diplazium esculentum), naturalized in Hawaii, and often called hio in local markets. Hio can be prepared the same way as bracken, but "is not known to have these anti-nutritional qualities so it can be eaten freely." The species name esculenta is Latin for edible, alluding to the use of this fern for food.Bracken has been used as fodder for animals, but it can injure or poison them. So, it often used as litter in animal pens.EtymologyThe generic name Pteridium is derived from the Greek pteris, fern, and pteron, wing or feather, in reference to fronds suggesting the spread wings of a bird.The specific epithet aquilinum, is Latin for eagle (Aquila).The varietial name decompositum is from the Latin de, very, and compositus, compound, in reference to the frond division.The varietial name decompositum is from the Latin de, very, and compositus, compound, in reference to the frond division.
nativeplants.hawaii.edu/plant/view/Pteridium_aquilinum_de...