Task: Sentence Expansion
Input (English): There are three species : " Cannabis sativa " , " Cannabis indica " , and " Cannabis ruderalis " .
Output (English): Three species may be recognized : " Cannabis sativa " , " Cannabis indica " , and " Cannabis ruderalis " ; " C. ruderalis " may be included within " C. sativa " ; all three may be treated as subspecies of a single species , " C. sativa " ; or " C. sativa " may be accepted as a single undivided species .