Cursed Crowfoot is a native erect annual or short-lived perennial, growing on stout, hollow, smooth stems to 20 inches high, with branching near the top and rooting at the base of the stem but rarely at nodes above that. Two varieties exist, photos below are of R. sceleratus var. multifidus.
The leaves are both basal and stem, both similar in shape but the upper leaves much smaller. Leaves are overall kidney shaped but with 3 to 5 palmate lobes, ranging from shallow to deep on the basal leaves. The margins of the lobes have large blunt teeth or you could call them secondary lobes. Basal leaves and stem leaves are stalked, with the stem leaves, being alternate, and having more slender lobes, whereas smaller leaves are on the flowering stems and are usually sessile with just 3 linear lobes. Basal and lower stem leaves have truncate or heart-shaped bases. All leaves are smooth, green and fleshy.
Inflorescence: Flowers are usually solitary and stalked at the tip of stems.
The flowers are 5-parted, about 1/3 inch across, with 3 to 5 (usually 5) yellow petals with rounded tips, 3 to 5 yellow green sepals with triangular tips that are at least as long as the petals, if not slightly longer, but they reflex downward, whereas the petals spread outward. Stamens number 10 to many, have broad yellow anthers, and surround the green receptacle composed of numerous pistils without styles. The nectaries of the flower are right on the base of the petals. A true corolla is lacking. The central receptacle elongates at maturity as the petals drop away. Sepals are not persistent.
Seed: Fertile flowers produce a cluster of dry brown achenes on the elongated central receptacle that are flat, smooth and kidney shaped, 1-1.2 × 0.8-1 mm in size, with a short triangular beak. Buttercup seeds need some cold stratification for germination, at least 30 days and some species require 60 days.
Varieties: Two are accepted. Var. multifidus where the seeds are smooth and the leaf blades are always parted with the segments lobed or parted and var. sceleratus where the seeds have transverse wrinkles and the leaf blades are lobed and may be parted but the segments are undivided or lobed.
Toxic: Plants of the Ranunculus genus are hazardous, particularly this species. See notes below photos.
Habitat: Buttercups comprise about 275 different species. Cursed Crowfoot grows in rich moist soil of marshes, swamps, ditches, preferring shallow standing water in full sun rooting from the stem base.
Names: Ranunculus sceleratus is in Ranunculus Sect. Hecatonia. The generic name Ranunculus, is from two Latin words, 'rana' meaning ' frog' and 'unculus' meaning 'little' and together they refer to a group of plants, many of which grow in moist places - like little frogs. The species, sceleratus, is Latin for 'cursed' and probably was used to describe this species as it is one of the most dangerous of the genus. See notes below the photos. 'Celery-leaf' comes from the shape of the lower leaves. The family name of Buttercup, used to be "Crowfoot', hence the continuation of the old name in many of the species common names. The author name for the plant classification, 'L.' refers to Carl Linnaeus (1707-1778), Swedish botanist and the developer of the binomial nomenclature of modern taxonomy.
Comparisons: While the leaves of this species are quite recognizable, here are a few other buttercups for comparison: Kidney-leaf Buttercup, R. abortivus; Swamp Buttercup, R. hispidus; Tall Buttercup, R. acris; Hooked Crowfoot, R. recurvatus; Bristly Buttercup, Ranunculus pensylvanicus.
Above and Below: Cursed Crowfoot will grow in standing water. Note the stout stem and fleshy leaves. The flower head. Note the sepals bend downward but are not fully reflexed. The green carpels in the center receptacle form the seeds. The stamens with their broad yellow anthers rise up around the receptacle. Drawing above from Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. 3 vols. Charles Scribner's Sons, New York.
Below: 1st photo - The lower leaf from which the alternate common name of "Celery-leaf" Buttercup is obtained. 2nd photo - The elongated heads forming seeds. Note the upper leaves are merely linear.
Below: Maturing seeds of Cursed Crowfoot - the beak eventually breaks off.
Notes: Cursed Crowfoot is considered a native plant, although it is also present in much of the rest of the world. In North America it is found throughout the continent except the Canadian Provinces of Nunavut and Labrador. In Minnesota it is widespread, with the counties not reporting it mostly in the NE section. Both varieties are noted by the DNR and the U of M Herbarium as being present in Minnesota but the MN DNR does not break down county location by variety. R. sceleratus is one of 16 buttercup species found in Minnesota. The photos above are of var. multifidus.
Toxicity: R. sceleratus has acrid and poisonous juices which can be fatal to browsing animals in the spring when the leaves are young and they eat a lot of them causing inflammation of the mouth and digestive tract. The foliage, if bruised and applied to the skin will raise blisters and sores that are not easy to heal. Mrs. Grieve (Ref. #7) notes that if the plant is boiled in water, the distillation is quite acrid and as it cools, crystals are deposited which are flammable. However, the boiled plant material looses its dangerous properties. Fernald (Ref. #6) writes that European authors have noted that in times past when food was scarce, R. sceleratus would be eaten as a spinach, being careful to first boil it in water and pour off the water which had extracted the acrid principal, anemonol. But "only in an emergency would one try it." [Note: Anemonol breaks down into the toxin protoanemonin, which has been said to poison bees that pick up pollen from Ranunculus species. - see this article on bees - pdf. and this article on Ranunculin and Anemonol - pdf]. It has also been reported that the Thompson Indians use the plant as a poison for their arrow points (D. E. Moerman 1986).
Legend: The legend of this plant family is this: Ranunculus, a Libyan boy who sang very beautifully, always wore green and gold silk. While singing in the woods, wood nymphs heard him and to get some peace and quiet, they turned him into a green and gold flower.
Eloise Butler wrote the following about Buttercups: "A number of the early flowering plants are members of the crowfoot family [such] as the anemones and buttercups. In the divided leaves of a crowfoot, as some of the buttercups are called, the early botanists saw a resemblance to a bird’s foot. The buttercups of Minnesota are not so much in evidence as the tall European buttercup [Ranunculus acris L.] the pest of the hay fields - farther east.
One early species, Ranunculus abortivus, [Littleleaf Buttercup] has so small a flower that a novice would scarcely notice it, and is surprised to hear it named a buttercup. Neither would a child be likely to apply the time-worn test of holding the flower to your face to learn if you love butter. This lowly buttercup [her text omits the common name] blooms sparsely on the prairie with the pasque flower. The specific name rhomboideus [prairie buttercup] indicates the shape of the leaf. The low, tufted R. fascicularis [early buttercup] has a larger flower, but is not conspicuously massed. Our two prettiest buttercups are aquatics - one with shining, yellow petals; the other with smaller white flowers and long, railing stems; and both bearing finely dissected leaves.
The large Crowfoot family is without strongly marked characters. Its plants have usually an acrid taste; the leaves are generally more or less cut or divided; the corolla is often wanting, and, when this is the case, the calyx is colored like a corolla; the stamens are numerous; the pistils vary in number from one to several; and all the parts of the flower are distinct or unconnected." Published April 30, 1911, Minneapolis Sunday Tribune [Entire Article]
References: Plant characteristics are generally from sources 1A, 32, W2, W3, W7 & W8 plus others as specifically applied. Distribution principally from W1, W2 and 28C. Planting history generally from 1, 4 & 4a. Other sources by specific reference. See Reference List for details.
Identification booklet for most of the flowering forbs and small flowering shrubs of the Eloise Butler Wildflower Garden. Details Here.
Friends of the Wild Flower Garden, Inc. Text and photos are by G. D. Bebeau unless otherwise credited. "www.friendsofthewildflowergarden.org"