Ranunculus sardous Crantz
Family - Ranunculaceae
Stems - To +25cm tall, multiple from base, densely pubescent (hirsute) below, less-so above, erect to decumbent, simple to branching above, herbaceous, from many fibrous roots (sometimes slightly thickened).
Leaves - Basal leaves often wilted by anthesis, long-petiolate, ternate. The lobes often divided again. Cauline leaves with slightly larger blades than basal leaves but with shorter petioles, becoming sessile near apex of stems, ternate. Petioles hirsute. Lobes of blades often divided or lobed again, ultimate lobes acute, entire, pubescent to glabrous. Lateral lobes typically sessile or on very short petiolules. Terminal lobe with a noticeable petiolule. Upper most leaves reduced to bracts.
Inflorescence - Single terminal flower. Peduncles expanding in fruit to +3.5cm long, with appressed pubescence.
Flowers - Petals 5, yellow, glabrous, obovate, 7mm long, 5mm broad, shiny above, sometimes notched at apex to obtuse or truncate. Stamens many (+/-40). Filaments to 2.5mm long. Anthers yellow, 1.5mm long, 1mm broad. Achenes smooth-sided or minutely papillose, with small curved beak to +.2mm long. Sepals yellowish, reflexed in flower, lance-ovate, to +5mm long, 3mm broad at base, pubescent to hirsute externally, scarious-margined, falling early (fugacious).
Flowering - May - August.
Habitat - Fields, meadows, roadsides, typically in moist soil.
Origin - Native to Europe.
Other info. - This species
is still fairly uncommon in much of Missouri, except for the bootheel region, where it has become abundant. A common springtime sight in the Mississippi Lowlands division is pastures turned a brilliant yellow by flowers of this species. It is a striking little plant but it should not be deliberately spread.
Photographs taken in Van Buren, MO., 5-26-03 and off Hwy 80 near Selma, AL., 2-19-05.