Good topic Matt. I think you may be right on genetics, but I think there could be other factors, such as soil and light. I have one spot with some darn nice wild root. I've dug some decent sized root there up to 40 years old. The strange thing is that the plants are tiny and rarely much size for berry pods! Maybe, 10\" tall. Just 2-300 yards away there are some seng w/ normal sized plants for around here. Not sure why exactly, but I suspect it could be genetics, soil and/or light. The soil has a lot of shale in it, sucks for digging! Some of these were from that spot. Normal sized root.