Ranunculus is a genus of about 600 species of plants in the Ranunculaceae. The petals are often highly lustrous, especially in yellow species.
Buttercups usually flower in the spring, but flowers may be found throughout the summer, especially where the plants are growing as opportunistic colonizers, as in the case of garden weeds.
In many perennial species, runners are sent out that will develop new plants with roots and rosettes at the distanced nodes.
The leafs lack stipules, have stems, are palmately veined, entire, more or less deeply incised, or compound, and leaflets or leaf segments may be very fine and linear in aquatic species.
The hermaphrodite flowers are single or in a cyme, have usually five (but occasionally as few as three or as many as seven) mostly green sepals and usually five yellow, greenish, or white petals that are sometimes flushed with red, purple or pink (but the petals may be absent or have a different, sometimes much higher number).
At the base of each petal is usually one nectary gland that is naked or may be covered by a scale. Anthers may be few, but often many are arranged in a spiral, are yellow or sometimes white, and with yellow pollen.
Poisoning can occur where buttercups are abundant in overgrazed fields where little other edible plant growth is left, and the animals eat them out of desperation.
Symptoms include bloody diarrhea, excessive salivation, colic, and severe blistering of the mouth, mucous membranes and gastrointestinal tract.
When Ranunculus plants are handled, naturally occurring ranunculin is broken down to form protoanemonin, which is known to cause contact dermatitis in humans and care should therefore be exercised in extensive handling of the plants.
Buttercups grow from seed or roots. The seed is difficult to germinate and takes weeks to sprout. Most people grow these plants from division of the roots. Divide plants in spring or fall. Or, they can be bought at your local garden store.
Buttercup plants like full sun to partial shade. They need a light soil that drains well. While they do not require a rich soil, this will help with their growth. They also prefer cooler soil.
Mulch around your plants, if grown in a sunny location. Add a general purpose fertilizer in the spring, and once a month afterward. Water established plants during dry periods and droughts.