RANUNCULUS: CHARACTERISTICS, SPECIES, CULTIVATION, CARE - BIOLOGY - 2025

Ranunculus is a genus of more than 400 species of herbaceous and perennial plants that belong to the Ranunculaceae family. Commonly known as French, marimoñas or buttercups, they are native to the Asian continent, although they cut wildly in America, Asia and Europe.

These are tuberous rooted plants that do not exceed one meter in height, the bright green leaves vary between lanceolate, palmate or segmented. The single or double flowers are arranged in a rosette and present a great variety of colors, generally blooming during spring or winter.

Ranunculus acris. Source: pixabay.com

Its cultivation is carried out for ornamental or commercial purposes, either for planting in pots, gardens and terraces, or as a cut flower for flower arrangements. It is considered a poisonous plant due to the presence of protoanemonin, a toxin with an irritant effect that can cause poisoning in livestock.

Most of the commercial species of the Ranunculus genus are annual or biennial and in the wild have aquatic or terrestrial habits. The main species include: Ranunculus aconitifolius, Ranunculus arvensis, Ranunculus asiaticus, Ranunculus auricomus, Ranunculus batrachium, Ranunculus bulbosus, Ranunculus glacialis, Ranunculus gramineus and Ranunculus platanifolius.

General characteristics

Appearance

Buttercups are perennial herbs with tuberous roots, gray-green stems, erect, branched and tomentose, regularly reaching between 10-60 cm in height. The stems develop from a robust root system from whose main root multiple secondary roots develop, being of the rhizomatous or bulbous type.

They are species of terrestrial or aquatic habits, the terrestrial ones of erect or creeping growth, as well as the foliage, it can be meager or exuberant. In species with aquatic habits, the stem develops submerged and flaccid, without any type of support tissue.

Leaves

The leaves are simple and petiolate, basal or caulinar, with serrated or lobed margins, measuring between 6-8 cm long. They have a conspicuous limbus segmented into irregular lobes, variable shapes and sharp terminations, generally light green in color.

The lower leaves develop directly from the root and acquire great morphological diversity. The caulinares are arranged alternately on the stem, they are few in number and have a lacinia shape.

In aquatic species, the submerged leaves have the form of capillary lacinias, those that are on the surface develop regularly. In species that develop basal leaves, they usually emerge from a single point at the base of the plant.

Ranunculus asiaticus. Source: pixabay.com

flowers

The simple or double flowers of 5-6 cm in diameter are composed of 5 triangular-shaped sepals and green color, and more than 5 petals of different colors. They emerge solitary in the axillary position from a long flower stalk or pubescent peduncle 15-18 cm long.

The double flowers have more than 20 petals that are grouped compactly, they are similar to roses and are known as "false roses." The wide variety of colors of buttercups ranges from white, yellow, or orange, to red, purple, or pink. Flowering occurs during spring and summer.

Fruit

Indehiscent nuts are nucules, achenes or polyaquenes 1-4 mm long. They are generally welded to a socket, are oblong, slightly curved and have small curved spines.

Taxonomy

- Kingdom: Plantae

- Division: Magnoliophyta

- Class: Magnoliopsida

- Order: Ranunculales

- Family: Ranunculaceae

- Subfamily: Ranunculoideae

- Tribe: Ranunculeae

- Genus: Ranunculus L.

Ranunculus ficaria. Source: pixabay.com

Etymology

- Ranunculus: the name of the genus comes from the Latin term «ranunculus» which means «little frog». Alluding to the fact that many of the species of the genus live, like frogs, near water.

Synonymy

- Coptidium

- Krapfia

- Rhopalopodium

Featured species

The great diversity of species of the Ranunculus genus includes plants with terrestrial or aquatic habits adapted to different types of ecosystems, but all with extremely attractive flowers. They are generally native plants to North America, Central America, Australia, Asia, and some areas of Europe.

Ranunculus acris

Ranunculus peltatus. Source: Wendy Cutler from Vancouver, Canada / CC BY (https://creativecommons.org/licenses/by/2.0)

Known as "buttercup", it is a plant with wild habits that develops spontaneously in meadows and fields. It blooms during spring and is characterized by its 5 golden petals. It is considered the easiest buttercup to propagate, due to its great adaptation to various types of soils and environmental conditions.

Ranunculus asiaticus

It represents the spice most used commercially to obtain hybrids, although its propagation requires special care in terms of temperature and solar radiation. It is a species adapted to Mediterranean conditions, reaches up to 40 cm in height and its double rose-like flowers present multiple shades.

Ranunculus bulbosus

A species known as "hairy grass", it is cultivated as an ornamental covering plant in large spaces or rocky areas due to its showy yellow flowers. It is an easy plant to grow as long as it is planted in full sun exposure and on well-drained soil.

Ranunculus ficaria

Perennial species that grows wild throughout Europe. Known as "lesser celandine," it is characterized by its bright green foliage and yellow flowers. It is cultivated as an ornamental plant in parks and gardens, however, it requires semi-shade and an adequate level of humidity.

Ranunculus peltatus

The "water buttercup" is an aquatic species that inhabits rivers and streams throughout Europe, North Africa and South-West Asia. It is characterized by its floating and submerged leaves, branches that reach up to 250 cm in length and its flowers with five white petals with a yellow base.

Ranunculus repens

Ranunculus bulbosus. Source: Xemenendura / CC BY-SA (https://creativecommons.org/licenses/by-sa/4.0)

It is considered an invasive species in wild conditions, being ideal as an ornamental to cover large areas of land. It is known as "bougainvillea" or "redellobas", it covers large areas thanks to the stolons of its roots, it has an erect stem, oval leaves and yellow flowers.

Culture

Ranunculus repens. Source: Algirdas at the Lithuanian language Wikipedia / CC BY-SA (http://creativecommons.org/licenses/by-sa/3.0/)

Buttercups multiply through seeds or by dividing bulbs or tubers.

Seeds

The seeds are obtained directly from the plant once the petals have detached and the floral structure has dried. The sowing is done directly in pots or germination trays, using a universal substrate and maintaining constant humidity.

It is not necessary to cover the seeds with substrate, in any case it should be kept protected from the sun until the seeds have germinated. When the seedlings have developed more than 6 true leaves, they can be transplanted to a larger pot or to the field.

Division

The best time to reproduce buttercups from bulbs or tubers is late summer or early fall. Vegetative structures are obtained from vigorous plants and allowed to dry in a cool, shady environment before planting.

After 2-3 days the tubers will be ready for sowing, it is recommended to break with a simple twist, without using tools. The divisions obtained are planted about 5 cm deep, although this depends on the size of the tuber.

Once sown, moderate irrigation should be applied, avoiding waterlogging the substrate, otherwise the tuber may deteriorate. In planters it is customary to maintain a planting spacing of 12-15 cm between plants, after 25-30 days the new seedlings begin to sprout.

Care

Weather

It is a plant that prefers cool and temperate climates, since the high temperatures of tropical climates tend to wilt the foliage. It develops effectively in climates with an average temperature between 12-23 ºC throughout the year, tolerates occasional frosts down to -5 ºC.

illumination

Buttercups do better in partial shade than in full sun exposure. As a general rule, they can receive only half a day of direct solar radiation, preferably the first rays of the day that are less intense.

It is recommended to grow under polyshade nets or around trees, so that the foliage filters solar radiation. In fact, diffused sunlight throughout the day favors its flowering.

Floor

They grow on loose, well-drained soils, preferably with a high content of organic matter. In parks and planters, it is advisable to prepare the ground before sowing by making an amendment with organic fertilizers or composted manure.

Irrigation

Irrigation should be applied regularly throughout its life cycle, in order to keep the substrate moist. However, waterlogging should be avoided and the ground should never dry out completely.

Subscriber

Provided that organic or mineral fertilizer has been applied at the time of sowing, only a nutritional contribution is necessary before flowering. The application of liquid fertilizers with high potassium content will allow to obtain an abundant and vigorous flowering.

Ranunculus field (buttercup). Source: pixabay.com

Plagues and diseases

Buttercups can be affected by common pests and diseases in ornamental garden plants. Among the most frequent pests are aphids, mealybugs, aphids, thrips, slugs and nematodes that usually affect tubers, flower stalks and young shoots.

In relation to diseases, buttercups are affected by phytopathogenic fungi when environmental conditions are adverse, mainly excess humidity. During the spring the presence of Oidium sp. on the foliage, in poorly drained soils, Pythium spp. and the incidence of Rhizoctonia spp. which causes rot of the bulb.

References

1. Diosdado, JC, & Pastor, JE (1996). Cytotaxonomic considerations of the genus Ranunculus L. (Ranunculaceae) in the Iberian Peninsula. In Anales del Jardín Botánico de Madrid (Vol. 54, pp. 166-178).
2. González, GL (1984). Notes to the genus «Ranunculus«. In Anales del Jardín Botánico de Madrid (Vol. 41, No. 2, pp. 470-474). Royal Botanical Garden.
3. Pizarro, J. (1995). Contribution to the taxonomic study of Ranunculus L. subgen. Batrachium (DC.) A. Gray (Ranunculaceae). Lazaroa, 15 (2).
4. Ranunculus. (2020). Wikipedia, The Free Encyclopedia. Recovered at: es.wikipedia.org
5. Ranunculus Asiaticus, Francesilla or Ranunculus (2020) See Plants: Facts about plants with their care since 2001. Retrieved at: consultaplantas.com
6. Buttercups. Care, Cultivation and Reproduction (2020) Guide to Growing Bulbs. Recovered in: bulbos.net
7. Sarmiento, L. (2018) Buttercup (Ranunculus). Gardening On. Recovered in: jardineriaon.com
8. Whittemore, AT (1993). Ranunculus. USDA. Agricultural Research Service. US Department of Agriculture.