Ranunculaceae, or Buttercup or Crowfoot Family is a large family of flowering plants with more than 60 genera and over 2,300 accepted species names. In North America there are approximately 25 genera and over 500 accepted taxa overall. Species are mainly herbaceous annuals or perennials, herbs, some woody vines and one shrub (Yellowroot, Xanthorhiza simplicissima); some perennial plants have rhizomes with new roots developing annually.
The Ranunculaceae have several large genera and small genera. Some of the largest genera in North America include; Delphinium (over 450 species), Thalictrum (over 150 species), Ranunculus (over 400 species), Clematis (over 370 species), Aconitum (over 330 species), Anemone (over 170 species), and Aquilegia (over 100 species). Ranunculaceae are native throughout the world in both the northern and southern hemispheres in temperate subtropical regions (east Asia), with the greatest diversities in temperate and cool regions in the northern hemisphere (North America).
Common family characteristics include: Leaves; basal and cauline, mainly alternate, some opposite and rarely whorled; leaves are simple (some are divided) or compound, most leaves with petioles, with or without stipules, lower leaf stem often sheathed. Leaves with margins entire, toothed or incised, pinnate or palmate venation, Stems; without thorns or spines, Flowers; bisexual, sometimes unisexual, showy or inconspicuous, 2 to 5 free sepals, radially or bilaterally (actinomorphic or zygomorphic) symmetrical, sepals and petals are not always clearly differentiated into a typical calyx and corolla (ie perianth is often petaloid), in most genera the petals are nectary near the base, flowers may be pedicellate) or sessile, the stamens and pistils are mostly numerous and separate from each other, Inflorescence; terminal or axillary, racemes, cymes, umbels, panicles, or spikes, some with solitary flowers. Fruits; mostly clusters of achenes or follicles.
The family Ranunculaceae contains some of the showiest wildflowers in Arizona and many popular wildflowers in North America and Arizona and the southwest deserts including; Aquilegia (Columbines), Delphinium (Larkspurs), Ranunculus (Buttercups), Aconitum (Monkhoods), Clematis (Clematis) and Anemone (Windflowers). The genus Ranunculus are also food plants for the larvae of some Lepidoptera species and some species are used as medicinal plants. Several species contain alkaloids, glycosides and other toxic properties poisonous to humans and livestock.