Ranunculus abortivus L.

Small-Flowered Crowfoot


CC = 1
CW = -3
MOC = 92

© DETenaglia

Family - Ranunculaceae

Habit - Biennial or short-lived perennial forb. Roots not tuberous (but sometimes enlarged basally).

Ranunculus_abortivus_roots.jpg Roots.

© SRTurner

Stems - Ascending to erect, to 70 cm, not rooting at the lower nodes, multiple from base, branching, glabrous, glabrous, without bulbils, the base not bulbous-thickened.

Ranunculus_abortivus_stem.jpg Node of stem.

© DETenaglia

Leaves - Basal leaves present at flowering, moderately to long-petiolate, the blade 1-4 cm long, 2-5 cm wide, kidney-shaped to more or less circular, simple, unlobed or sometimes the innermost 3-lobed, the base shallowly to deeply cordate, the margins scalloped. Stem leaves sessile to short-petiolate, the blade deeply 3-or 5-lobed or -compound, the segments narrowly lanceolate to obovate, the broader ones toothed or narrowly lobed along the margins.

Ranunculus_abortivus_basal_rosette.jpg Basal rosette.

© DETenaglia

Ranunculus_abortivus_basals.jpg Basal leaves.

© DETenaglia

Ranunculus_abortivus_leaves.jpg Cauline leaves.

© DETenaglia

Ranunculus_abortivus_leaf1.jpg Stem leaf, adaxial.

© SRTurner

Ranunculus_abortivus_leaf2.jpg Stem leaf, abaxial.

© SRTurner

Inflorescence - Open panicles or single flowers at branch tips. Peduncle to 9 cm long, glabrous.

Ranunculus_abortivus_inflorescence.jpg Inflorescence.

© SRTurner

Flowers - Sepals 5, 2.0-2.5 mm long, spreading or reflexed from the base with age, lacking a transverse fold, plane. Petals 5, 1.5-3.5 mm long, 1-2 mm wide, elliptic, slightly shorter than the sepals, yellow, glabrous. Stamens 20 or more, from base of pistils. Filaments and anthers yellow. Pistils numerous, forming a globose head to 5 mm long. Style present but minute.

Ranunculus_abortivus_flower.jpg Flower close-up.

© DETenaglia

Ranunculus_abortivus_calyx.jpg Calyx close-up.

© DETenaglia

Fruits - Head of achenes 3-6 mm long at maturity, ovoid-globose, the receptacle sparsely hairy. Achenes 1.4-1.6 mm long, turgid, the dorsal margin broadly and bluntly angled, the wall thick, smooth, glabrous, the beak 0.1-0.2 mm long, slender, curved.

Ranunculus_abortivus_fruits.jpg Fruit cluster.

© SRTurner

Flowering - March - June.

Habitat - Streambanks, pond margins, forests, prairies, ledges of bluffs, pastures, fields, orchards, lawns, ditches, roadsides, and open, disturbed areas.

Origin - Native to U.S.

Lookalikes - Other species of Ranunculus, especially R. micranthus.

Other info. - This is a very common plant throughout Missouri, also ocurring across most of the continental U.S. except for a few western states. It is easily recognized by its small, pale yellow flowers, basal leaves, and generally sparse habit. It strongly resembles R. micranthus but can be distinguished from that species by its glabrous stems and basal leaves with cordate bases. It is also somewhat weedier than R. micranthus, occurring in lawns and pastures in addition to less disturbed habitats. It tends to prefer areas of abundant moisture.

The genus name Ranunculus is derived from Latin for "little frog," probably in reference to the common trait of many species to grow near or in water. The common name "crowfoot" refers to the typically 3-fingered shape of the upper leaves. An old children's game involves holding a buttercup flower up to the chin, whereupon a yellow reflection supposedly reveals a fondness for butter. Most species of Ranunculus, including this one, contain an acrid sap which is toxic and can cause dermatitis in some individuals. The bitter taste of the plants deters grazing, but livestock forced out of desperation to feed on the plants can be poisoned.

Photographs taken off Northwood Rd, Platte County, MO., 3-28-00, in Brown Summit, NC., 3-14-03, and off Lee Rd 54, Auburn, AL., 3-3-05 (DETenaglia); also near Labadie, Franklin County, MO, 4-23-2014, and at Pacific Palisades Conservation Area, Jefferson County, MO, 4-2-2019 (SRTurner).