Devil's tongue, also called snake palm, voodoo lily, elephant yam or umbrella arum, is a tropical plant that features a large purplish red flower similar to a lily. Devil’s tongue is actually related to the lily, as it is part of the arum or philodendron family. The devil’s tongue is a large plant, growing up to four feet tall, with the leaves spreading out from the central stalk like an umbrella. This rare tropical plant is grown for the edible tubers it produces in many parts of Asia, but flowering varieties are becoming more popular with specialty gardeners. Its Latin name is Amorphophallus konjac, and it is related to other umbrella arums like the corpse flower.
The devil’s tongue’s close cousin, the corpse flower, has the similar Latin name of Amorphophallus rivieri. The corpse flower is famous for a very strong odor like rotting flesh, which attracts insects to help with pollination. Not all types of arums have this distinctive foul odor, however, and many ornamental varieties of the devil’s tongue flower do not. While ornamental varieties are being increasingly sold in the West, the devil’s tongue has been traditionally cultivated for its edible tuber in Japan, China and Indonesia.
The devil’s tongue plant produces a very large tuber, which can grow up to a foot across. The tuber looks somewhat like a yam, which may be the origin of the name elephant yam. The tuber, called konjac, is edible in some varieties, and is a staple starch food in Japan. Konjac is pounded into flour and sometimes used to make a jelly. Konjac gel is often used as a vegan substitute for gelatin. The tuber is cut into blocks like tofu, and is used in many soups and stews.
Devil’s tongue plants should be grown indoors and treated as any indoor tropical houseplant. This rare tropical plant is not very hardy out of doors, and needs fertilizer and care to bloom. Gardeners should move the plant to larger pots as it grows to give plenty of room for the developing tuber. The plant will flower when the tuber is developed. Many people who have grown these rare plants have owned them for years without knowing that they flower. Regular fertilizations can hasten blooming. Because they are used to tropical climates, the plants usually go dormant in the winter, but must be protected from freezing.