Dioscorea amaranthoides var. metallicaDioscorea amaranthoides var. metallica at a glance: Dioscorea amaranthoides var. metallica is a seasonal climbing yam that sends up twining annual stems from a persistent underground rootstock, then retreats again when growth ends. Its main draw is the foliage: dark green leaves with a metallic sheen that shifts with angle and light, giving the plant a cooler, more reflective look than green vines. During active growth it prefers bright indirect light