Simplify the following text for a Grade 6 native English-speaking person.
Original: The lower altitude site is estimated to have about 50 mature plants , making it the most endangered Drosera species , since it is threatened with extinction in the wild .
Simplified: On the lower-altitude site , there are about 50 mature plants . For this reason , D. regia is the most endangered Drosera species , since it is threatened with extinction in the wild .