There are easier ways to grow starchy roots, but if you want a spectacular veg patch or an edible flower bed then Lilium lancifolium ‘Splendens’ (tiger lily) is a plant that erases the difference between the two. Its ornamental appeal lies mostly in its striking spotted orange flowers (which inevitably raise the question, why tiger rather than leopard lily?) the petals of which curve right back to the stem, exposing long stamens, giving an overall effect that always puts me in mind of a jellyfish when viewed from the side.
There are two edible parts. The flowers can be eaten, although an internet meme holds that the pollen causes vomiting. Eat the Weeds suggests that this arose from the fact that all parts of the plant are indeed poisonous to cats and quotes one author who has eaten the pollen with no ill effects. Next flowering season I’ll try some (tentatively) myself and let you know. The bulbs (which I have tried myself) can be either fried or boiled. They have a mild taste and a starchy texture similar to a floury potato. They are traditionally cultivated in Asia as a food crop.
Spectacular as the flowers are, they are completely sterile and this lily doesn’t produce fertile seed. Instead, it can be propagated by splitting the bulb or by potting up the handy little bulbils that grow along the length of the stem. These are best grown on in pots for the first year, then planted out and grown on for two or three more years until they are big enough for flowering and/or eating. If anyone would like to give it a go, I sometimes have bulbils in my seed list. Tiger lily likes a warm, sunny spot with freely draining soil.