A very brief listing of shrubs of the american southwest: More to be added later!
The Crossosoma Family in the American Southwest: Crossosomataceae
The Ephedra Family in the American Southwest: Ephedraceae
The Silktassel Family in the American Southwest: Garryaceae
The Mock Orange Family in the American Southwest: Hydrangeaceae
The Oleaster Family in the American Southwest: Oleaceae
The Buckthorn Family in the American Southwest: Rhamnaceae