Ranunculus micranthus Nutt.
Family - Ranunculaceae
Stems - Typically around 40cm tall, erect, herbaceous, with thick roots, villous(at least below), branching above to simple, single or multiple stems from base.
Leaves - Basal leaves petiolate. Petiole to +8cm long, villous. Blade typically with truncate or subcordate base, suborbicular to broadly ovate or reniform, mostly glabrous but with a few villous hairs below, to +3cm broad, +2.5cm long. Cauline leaves becoming sessile above, 3 to 5-lobed, sparse villous above and below. Lobes often divided again, ultimate divisions entire or crenate.
Inflorescence - Terminal single flowers on long peduncles. Peduncles sparsely to densely villous, to 5-6cm long but typically less.
Flowers - Petals 5, yellow to pale yellow or with some white, lanceolate, spreading, to 4mm long, 1.5cm broad, glabrous. Stamens many (+20), borne below the pistils. Filaments minute, -2mm long. Anthers yellow. Pistils grouped into a globose head to 5mm long, 3.5mm in diameter. Sepals 5, reflexed to spreading, cupped, sparsely villous on exterior, ovate to elliptic, 3mm long, 2mm broad. Achenes subrotund, surface pitted, to +/-1.5mm in diameter, with beak to .3mm long.
Mature flower with fruits.
Flowering - March - May.
Habitat - Slopes, ravines, bottoms, open rocky woods, disturbed sites.
Origin - Native to U.S.
Other info. - This plant
is very similar to another species, R. abortivus L.,
but the latter has glabrous stems, typically strictly reniform basal leaves,
and less divided cauline leaves.
Photographs taken off Northwood Rd., Platte County, MO., 4-20-00.