wild potato, heartleaf horsenettle, or heartleaf nightshade (see attestations)
a plant with an edible root, or the root itself
"It is commonly known as cimatli (along with S. ehrenbergii), heartleaf horsenettle, or heartleaf nightshade. This is one of the few wild potato species that was commonly used as food. The Aztec and the Chichimeca ate S. cardiophyllum and the practice continues in some parts of Mexico today (Johns 1990). In fact, there was at least one farm that was growing S. cardiophyllum, S. ehrenbergii, and S. stoloniferum for market in Jalisco as recently as 2010 (Villa Vazquez 2010)." The leaves are shaped like hearts.