Why onion and potato are called modified stems?
, and that’s exactly what you see sprouting on the potato, arising from the potato’s “eyes.” Tubers are actually swollen portions of underground stems (stolons) and, as we’ve seen, stems have nodes, and buds arise at nodes. One reason it’s hard to think of the potato with its sprouting eyes as an underground stem is that no nodes are obvious. If you were a scientist able to watch the potato’s cells divide and grow from the very beginning you’d see that in the very early stages of development the potato had recognizable nodes, and then you could watch the nodes develop slowly into the potato’s eyes, and the eyes would have buds associated with them, just like a normal tree-branch node.
