Taxonomy is comparative biology of traits and taxa. The most effective taxonomy is monographic in scope1, studying taxa across their entire geographic distribution2,3. This seminar will illustrate, with examples, from a recently published monograph1 of all morning glories (Ipomoea) in the New World, the potency of a monograph for completing the global inventory of species2,4, as well as providing insights on the evolution of a major crop2,3, transoceanic contact theories3 and divergence time analyses5-7.