Plant · P-267

Yam

Dioscorea alata

Yam (Dioscorea alata) produces both an underground tuber and small aerial tubers, called bulbils, that form in the leaf axils through summer - and where the season is too short to fully bulk the root tuber, the bulbils become the real harvest instead of a bonus. The purple-fleshed forms are the ube used in Filipino cooking, and their anthocyanin pigment doubles as a natural food dye. Every part must be cooked, never eaten raw - the raw tuber is toxic and causes narcosis. Its vigorous climbing vine has to be lifted and stored like a dahlia where winters bring hard frost, but that same frost also keeps in check the aggressive, tree-smothering growth that makes it a listed invasive in frost-free regions.