The family is widely distributed .
Is the third - largest land plant family in terms of number of species , behind only the Orchidaceae and Asteraceae , with about 751 genera and some 19,000 known species .
The family is widely distributed , and is the third - largest land plant family in terms of number of species , behind only the Orchidaceae and Asteraceae , with about 751 genera and some 19,000 known species .