Final answer:
The two major types of marijuana are Cannabis sativa and Cannabis indica, with Cannabis being a dioecious plant, having separate male and female flowers on different plants.
Step-by-step explanation:
The two major types of marijuana are Cannabis sativa and Cannabis indica. While Cannabis ruderalis is also a type of cannabis, it is not as widely recognized or used as the former two.
Additionally, the classification of flowering plants based on their reproductive structures includes dioecious plants, like Cannabis, where the male and female flowers are on separate plants.
This is crucial for understanding the biology and cultivation of marijuana.