Buttercups. The word brings to mind a field of yellow flowers, or perhaps a young girl sniffing the flower and dusting her nose with pollen. And indeed, some of the flowers in this family, the Ranunculaceae, do make you think of a little cup filled with bright yellow butter. And some don’t.
It’s the exceptions to the rules that make this family a bit tricky to identify.
The Ranunculaceae family, known more familiarly as the buttercups, has over 2,000 species in 43 genera, and can be found all over the world. For the most part, they are either annuals or perennials, although there are some woody plants as well, such as those in the genus Clematis. The flowers typically have four to five petals (an indication that they’re dicots, with their seeds having two cotyledons). Most are single blossoms, but some are arranged in groups, with stems that may be branched or form spikes. Most have radial symmetry, like a pie, but exceptions include monkshood and delphiniums (below), which are bilaterally symmetrical, with two mirrored sides (like humans).
Once the flowers have faded, some buttercup family members form achenes[i]. Clematis, pasqueflowers, and ranunculus are some examples. (Strawberries, sunflowers, and quinoa, plus many more plants, also form these seed structures.)
Others form follicles—hellebores, winter aconite, and love-in-a-mist, to name a few. Again there are exceptions. Those plants in the genus Actaea (baneberries, bugbane, and cohosh) form berries.
Buttercups have been around a long time, longer than most other plants. They are considered botanically “simple,” meaning that the parts of the flowers—the petals, sepals, stamens, and pistils—are all separate from one another. Additionally, the number of these parts varies from flower to flower. There may be 23 petals, or none, 15 sepals, or 3 (and those may look like petals). Likewise, there may be many stamens and/or pistils, or just a few.
To identify a buttercup in the field, you need a flower and probably a magnifying glass. Examine your blossom, looking for multiple pistils. Most plant families only have one, so if you see more than that, it’s a good indication that the plant is in the Ranunculaceae. Then, to confirm your ID, look at the tips of the pistils. Are they hooked? If so, it’s more than likely your plant is a buttercup. While not all buttercups have hooked pistils, many do.
There’s one more test you can do in the field. You can taste the flowers. Many buttercups are considered poisonous, but you aren’t going to eat them. You’re merely going to taste them, then spit them out again. The plants contain protoanemonin glycoside oils, which have a biting, acrid flavor. However, please avoid doing this if you think you’re dealing with a member of the tribe Delphinieae, which includes delphiniums and larkspurs (Delphinium sp. and Consolida sp.) and monkshood (Aconitum sp.), as they contain poisonous alkaloids. Aconitum includes a plant commonly called Queen of Poisons, which should be an indication of their toxicity!
While few buttercups are considered edible, they feed our need for beauty. From Trollius and hellebores, to anemones and pasqueflowers, many Ranunculaceae members decorate our gardens. Some of our most beloved wildflowers are in this family; imagine Colorado’s mountains without any columbines. No matter where you see them, the next time you run into one of the buttercups, take a good look, and appreciate what a fine family this is.