Introduction to the Umbilicus rupestris or navel of Venus
The focus of the rock, commonly referred to as navel of venusIs a succulent and perennial plant It belongs to the Crassulaceae family. It is recognized for its unique rounded leaf shape with a central depression, evoking the image of a navel, hence its vernacular name. This species stands out not only botanically for its adaptability and resilience, but also for its extensive tradition of medicinal uses and for being a prized wild food in various European cultures.
Etymology and other common names
The scientific name umbilicus comes from Latin and literally means "navel", referring to the characteristic sunken shape of its leaves. The epithet rupestris It translates as "living on rocks," indicating its preferred habitat. In addition to the well-known name of Venus's navel, this plant has a multitude of vernacular names in Spain and Europe, reflecting its popularity and widespread presence. Some of these names include: sombrerillo (small hat), ombligero (navel hat), monk's ear (friar's ear), abbot's ear (abbot's ear), vasillos (small hats), curalotodo (cure-all), wall tobacco (wall tobacco), rooftop bells, among many others.
Classification and detailed taxonomy
- Domain: eukarya
- Supergroup: Archaeplastida
- Phylum: Chloroplastida
- Division: Streptophyta
- Subdivision: Spermatophytina
- Class: Magnoliopside
- Order: Saxifragales
- Family: Crassulaceae
- Gender: umbilicus
- Species: Umbilicus rupestris (Salisb.) Dandy
In the botanical literature, several synonyms have also been used to refer to this species, such as Cotyledon umbilicus-veneris, Cotyledon neglecta, Umbilicus pendulinus y Umbilicus vulgaris.
Botanical characteristics of the Venus navel
The focus of the rock is a herbaceous, succulent, perennial plant which can reach heights from 9 to 60 cm. It has a glabrous form (absence of hair), with a subspherical stem and a generally erect and simple stem, branching only occasionally.
- Sheets: Fleshy and peltate, the leaves basal They measure between 1,5 and 4 cm in diameter, are rounded, concave, and have scalloped edges. They have a central petiole measuring between 4 and 25 cm.
- Stem leaves: Smaller and variable in shape, from subspatulate to lanceolate, sometimes toothed.
- Inflorescence: Spikey, in the form of an elongated cluster that occupies 60–90% of the stem's length; it can also appear paniculate on very rare occasions. The filiform or elongated bracts measure between 2–6 mm.
- Flowers: Pendulous, with peduncles measuring 1,5 to 9 mm. Subacute sepals measuring 1-2 mm. The tubular or subcampanulate corolla measures between 6 and 9 mm and can be straw-colored or light greenish. The corolla segments are broadly triangular and acute, overlapping widely.
- Reproduction: The plant produces a large amount of ovoid seeds dark brown in color, about 0,5-0,7 mm.
The focus of the rock It shows remarkable tolerance to difficult environments thanks to the succulence of its leaves, which allows it to retain water during periods of drought.
Natural habitat and distribution
The navel of Venus is specially adapted to colonize different rocky areas, wall cracks, stone walls, shady slopes, and old roofs. It prefers cool, humid environments, although it can also be found in semi-shaded areas and, occasionally, under the cover of scrubland, especially in areas where vegetation retains ambient humidity.
- Altitude: It can grow from sea level to altitudes of 2000 meters, demonstrating great ecological plasticity.
- Substratum: It tolerates both acidic and basic soils, as long as there is a certain level of humidity without waterlogging.
- Distribution: It extends throughout the Mediterranean basin, encompassing Portugal, Spain (including the Balearic and Canary Islands), France, Great Britain, Ireland, Bulgaria, Italy, and other regions of Western Europe. It is especially common on the Iberian Peninsula and can even be found in urban areas and on city walls.
The adaptability of this species to urban and rural environments, as well as to different types of rock formations, explains its wide range of names and its presence in both natural and human-made environments.
Ecology and adaptive behavior
The focus of the rock It is one of the few plants capable of growing in extremely poor, rocky substrates, where other species would struggle. Its ability to live in crevices allows it to survive competition and take advantage of the moisture accumulated in walls and fissures.
- Flowering: It generally blooms from spring to mid-summer. Its pendulous flowers are grouped in long, highly visible clusters.
- Resistance: It withstands occasional frosts down to -15°C and drought conditions thanks to the accumulation of water in its leaves. During dry periods, it can close its stomata during the day and open them at night, optimizing water loss.
- New outbreak: After flowering and seed dispersal, the above-ground part may die back, but the underground base will sprout again when favorable conditions arrive.
The species also contributes to improving the microhabitat in rocky areas, facilitating the arrival of new plants and enriching local biodiversity.
Ecological indicators and phytosociological relationships
Light: It adapts to both full light and semi-shade, although it usually prefers locations where the sun does not shine directly on it all day long.
Temperature: It thrives in warm or temperate areas, although it tolerates some cold and episodes of extreme heat.
Humidity: Indicative of moderate dryness. It prefers consistently cool or slightly moist soils, but does not tolerate waterlogging.
soil pH: It is usually found in weakly acidic to neutral soils (pH 4.5 – 7.5).
Nutrients: It grows best in nitrogen-poor substrates and does not tolerate saline environments.
Biological type: Hemicryptophyte (with buds at or just below the soil surface) and geophyte (it renews its visible parts from underground stems, such as rhizomes).
It integrates into plant communities typical of walls, rocks and environments with a certain presence of nitrogen, forming part of associations of the type Parietarietalia (Parietarietea).
Reproduction and dispersal
The navel of Venus reproduces mainly by seeds, which are dispersed locally by the wind or by falling into nearby cracks and soil. The seeds lack specific adaptations for long-distance dispersal, but the plant compensates with high seed production and a high germination rate.
For propagation in urban gardens or orchards, it is sufficient to spread mature inflorescences in an appropriate substrate to obtain seedlings adapted to poor and rocky substrates.
Medicinal properties and traditional uses
- Analgesic and anti-inflammatory properties: Traditionally, fresh leaves or the juice obtained from the plant have been applied to the skin to soothe inflammation, burns, eczema, chilblains, boils and sores.
- Healing and vulnerary properties: It is known for its effects on the acceleration of the healing of wounds, cuts and minor burnsPoultices and preparations made from the leaves have been a popular remedy in European rural medicine.
- Diuretic properties: The consumption of the juice or infusion of crushed leaves and stems is used as diuretic, facilitating the elimination of liquids and helping to retain them.
- Astringent and lenitive properties: It protects the skin and can be applied as a soothing agent in case of irritations or bites.
- Antiseptic use: The juice has been traditionally used to treat purulent otitis and mild infections for its antiseptic properties.
- Hepatoprotective properties: Its use is cited for liver inflammation and to help liver function.
- Antioxidant activity: Several recent studies mention the presence of flavonoids and polyphenols (myricetin and glycosides), which contribute to the elimination of free radicals and cellular protection.
- Antibacterial capacity: There are references to trials where it inhibits the growth of resistant bacteria, which justifies some of its traditional uses in wound healing.
Modern trials have ruled out cytotoxicity at typical concentrations, consolidating its applications in folk medicine, although caution is recommended when using it internally for prolonged periods or without professional supervision.
Culinary uses of the navel of Venus
The young and fresh leaves of Venus's navel are groceriesThey are mainly used raw, in salads or as a decorative element in modern haute cuisine, taking advantage of their meaty texture and slightly acidic flavorThey can also be pickled in vinegar for preservation and later consumption.
It is important to harvest the leaves when they are still tender, as as they age, their flavor intensifies and can become slightly bitter or unpleasant.
Main active ingredients
- Trimethylamine
- Various paraffins
- Clorofila
- Phytosterin
- Polyphenols and flavonoids with antioxidant action
- Omega-3 fatty acids
These compounds justify many of their applications both in traditional medicine and in the human diet, especially for cardiovascular protection and skin health.
Differentiation and precautions
It is important not to confuse The focus of the rock with other similar species such as Hydrocotyle vulgaris, which may have similar leaves before the flowering stage. However, Hydrocotyle grows in stagnant aquatic environments such as ponds and swamps, and umbilicus It prefers walls or surfaces where water runs off and doesn't puddle. Hydrocotyle vulgaris is not edible and should not be used for medicinal purposes.
Cultural and ethnobotanical relationship
The navel of Venus has been protagonist of legends and popular traditionsHippocrates recommended it to promote the birth of sons, and various magical and healing beliefs have been associated with the plant. Its evocative aesthetic has even inspired Renaissance painting, and it remains valued today in ethnobotany and rural culture.
Measures for its conservation
In urban and rural environments, the preservation of the navel of Venus involves respect living walls and rock ecosystemsIn many cities and towns, it is recommended not to over-clean stone walls to allow this and other species to continue beautifying and maintaining local biodiversity. Various environmental education initiatives promote the value of these plants as decorative and functional elements in human-made landscapes.
How to collect and propagate Umbilicus rupestris
To spread the navel of VenusSimply pick a dried inflorescence before the seeds are fully dispersed and gently shake it over the desired location, whether a wall, a rock, or even a pot with a stony substrate. The seeds germinate easily and can establish quickly if kept in a cool, slightly humid environment.
Other vernacular names and their meaning
In addition to those already mentioned, Umbilicus rupestris is known by a wide variety of popular names in different linguistic communities of the Iberian Peninsula and Europe: cuquiellos, gorros de las paredes, couselo, orma belarra, trutxas, barretets, among others. All of them refer to the shape, habitat, or traditional uses of the plant.
Through the centuries, The focus of the rock It has remained a fundamental part of European culture and nature. Its ability to adapt to every rocky terrain and its medicinal and culinary versatility make it a plant worthy of admiration and conservation, bringing beauty, health, and tradition to any landscape where it is found.