Simplify the following text for a Grade 8 native English-speaking person.
Original: Rhododendron catawbiense , the most widespread rhododendron of the Appalachian Mountains , is the state flower of West Virginia , and is in the Flag of West Virginia . Rhododendron macrophyllum , a widespread rhododendron of the Pacific Northwest , is the state flower of Washington .
Simplified: Rhododendron is a large genus of flowering plants .