Are places where wild animals are kept in protected environments under human care
Provides the actual account of habitat and distribution of plants of a given area.
Are based on the contrasting characters generally in a pair called couplet.
Have collections of living plants for reference
Keys are generally analytical in nature. The keys are based on the contrasting characters generally in a pair called couplet. It represents the choice made between two opposite options. This results in acceptance of only one and rejection of the other.