Angelica keiskei, more widely known under the japanese name of Ash*taba (アシタバ or 明日葉, ash*taba, literally "Tomorrow's Leaf") is a not frost tender perennial plant from the angelica genus endemic to Hachijōjima. Harvesting a leaf at the break of day results often in a new sprout growing over night, being visible the following morning. Traditional it is seen as a major contributor to the supposedly healthier, extended lives of the local residents what may be based on its substantial levels of vitamin B12 and chalcones that are unique to this species of angelica. At one point in Edo period the haulms yellow sap was effective used in the external treatment of smallpox, which prompted Kaibara Ekken to describe the herb in his Yamato honzō (大和本草) under the name of ash*tagusa (鹹草) as "a powerful tonic drug". In folk medicine it is attributed to be diuretic, tonic, improve digestion, and applied topically to speed wound healing and prevent infection. Also its nutritive qualities are said to be the factor behind the originally insular exiles' never waning stamina in the face of their arduous compulsory labor. For similar reasons, it serves as pasture for cows all over the place, reckoned to improve the milks quality as well as the yield and keeping them healthy at the same time. It has to be pointed out that most of this claims have yet to be proven in clinical trials, while studies substantiated furocoumarins in several plant components; an agent known to increase skin sensitivity to sunlight and may cause dermatitis. Nonetheless modest conditions for cultivation and fast rate of growth have led many locals to plant ash*taba in herb gardens, flower pots and even backyards. These days the main usage of the edible aerial parts, in particular the stipes and leaves, as well as its taproot, is in regional cuisine, where they are prepared as soba, tempura, shōchū, tea and ice cream amongst others.
