Hemp flower remains legal in most states, and it is one of the least expensive ways to get CBD and other cannabinoids into your system. The 2018 Farm Bill made hemp legal federally, and the FDA does not appear to have jurisdiction over the sale of agricultural products such as hemp flower.
Beginning with the 2019 Fall harvest the online market has seen a new type of Cannabis for sale. CBG (Cannabigerol) hemp flower refers to the female flowers of hemp plants that are bred to produce primarily CBG rather than CBD.
Patagonia created an excellent video putting hemp into perspective.