Amorphophallus paeoniifolius aka Elephant Foot Yam

Amorphophallus paeoniifolius is also called elephant yam. It belongs to the arum family. Its native range runs from tropical and subtropical Asia to northern Australia. It grows in places with a dry season. Wild plants grow in forests, scrub, and dry valley grasslands. They also grow in shade where loose leaf litter lies. The plant grows both wild and as a crop. Farmers grow it for food in lowland tropical Asia.

This herb lives for years and has a large underground tuber. It grows one or two large leaves each year. Sources give smaller plant heights of about 2.5–2.6 feet [0.75–0.8 metres]. Useful Tropical Plants also reports leaves reaching 6.6 feet [2 metres]. That source gives tuber weights up to 25 kilograms. PFAF reports corms, or swollen underground stems, reaching 1.6 feet [0.5 metres] across. Corms may weigh nine kilograms at harvest after three years. The flower head bears both male and female flowers. The female flowers sit below the male flowers. Flies carry pollen for the plant.

Elephant yam needs warmth and moist soil as it grows. PFAF lists USDA hardiness zones 11–12. Its crop guide gives a range of 25–35°C. Deep, rich soil that is a little acid gives good crops. Sandy soil and loam suit it, but heavy clay does not. It can also grow in neutral and mildly alkaline soil. Young plants need some shade. Once plants take hold, they can grow without shade. Dry spells help the corm grow. Growers often raise the crop over three years.

The plant suits shaded beds and woodland food gardens. Farmers also grow it under coconut, banana, and coffee crops. In some regions, it feeds people when rice harvests fail. The cooked corm adds starch to meals. Growers may chop and dry it or make a curd. Its mild taste takes on flavours from other foods. PFAF lists leaves as a part people can eat, too. It also records use of the root as medicine. These uses include treating gut complaints and rheumatism.

Food use needs care, as raw corms have an acrid taste. PFAF says to cook them well before eating them. Useful Tropical Plants says wild tubers are toxic and not fit to eat. Both sources warn of possible harm from calcium oxalate. Some of this warning rests on evidence from the wider family. PFAF urges extra care for people prone to kidney stones. Its weed review does not flag this plant as weedy.