Norça (Tamus edulis)

A native climbing plant of the yam family (Dioscoreaceae), cultivated at Achadas da Cruz (‘plateaus of the cross’) and Porto Moniz (‘Moniz’s harbour’) for its edible tubers. In the wild it has been found only at Garajau (‘tern’). Frutuoso mentions it on Porto Santo (‘holy harbour’), where it is now completely extinct. It has dioecious, purple flowers and heart-shaped, acuminate leaves with 9 veins.