Globally, it consists of around 1,800 species in about 50 genera. The Ranunculaceae occurs throughout the world, but is most abundant in temperate and cool regions of the northern and southern hemispheres. The Ranunculaceae includes several attractive species, but is not an economically important family. The commercially available species are almost all ornamentals. A few of the more common ornamentals in this part of the world are Anemone , Aquilegia , Cimifuga , Clematis , Delphinium , Helleborus , Nigella , Ranunuculus, Thalictrum , and Trollius .
Some genera are important as poisonous plants.
The poisonous properties of Aconitum and Delphinium are well known, particularly to those in involved with cattle. Many, possibly most, other genera contain poisonous species. A drink of Aconitum tea was the lethal drug used for giving the death penalty in ancient times and infirm old men on the island of Ceos were also forced to commit suicide with Aconitum . It is not a nice way to go. In other words, a genus may differ from other genera in its family by one or two characters without being kicked out of the family, so long as it resembles the other genera in other respects.