Medusa's Head

Euphorbia caput-medusae

Raquel Patro

Published in

Euphorbia caput-medusae - Medusa's Head

Among the succulents that adorn our homes and gardens around the world, few possess an appearance as peculiar as the Medusa’s Head, from the species Euphorbia caput-medusae. The scientific name “Euphorbia caput-medusae” was coined by Carl Linnaeus himself in 1753, in the Species Plantarum, reflecting the plant’s remarkable resemblance to the head of Medusa, one of the three Gorgons from Greek Mythology, an iconic figure known for having snakes in place of hair.

The Euphorbia caput-medusae originates from the Cape region in South Africa, stretching from Namaqualand to Mossel Bay. This habitat is characterized by sandy plains, with typical renosterveld vegetation and coastal rocky outcrops, where the plant adapts well to both sandy soil and rocky crevices. It is a typical representative of the renosterveld vegetation on the slopes of Signal Hill and Devil’s Peak in Cape Town, a region of Mediterranean forests, woodlands, and shrubland biome, but is seriously threatened due to urbanization and agriculture.

Radially distributed branches around the globular caudex of Euphorbia caput-medusae
Radially distributed branches around the globular caudex of Euphorbia caput-medusae

The natural environment of the Medusa’s Head is marked by wet winters and dry summers, which directly reflect on its cultivation needs. Adapted to survive arid conditions, this succulent has developed a central caudex—a specialized stem for water storage—that allows it to withstand periods of drought.

The caudex of Euphorbia caput-medusae is a globular stem, almost completely subterranean, which can reach up to 8 inches (20 cm) in diameter. It merges with a deep, succulent main root to absorb and store water and nutrients. From this short and central caudex, branches emerge, creating an appearance reminiscent of the mythical Medusa’s hair.

The branches of Euphorbia caput-medusae are cylindrical, succulent, and serpentine, extending in various directions from the caudex. They can vary significantly in length, reaching from 7 to 30 inches (18 to 75 cm), and have a diameter of 0.4 to 1.2 inches (10 to 30 mm). The surface of these branches is marked by prominent, obliquely elongated tubercles, which confer a knobby, segmented texture, like snake scales. The tips remain elevated compared to the length, giving them a snake-like appearance.

Detail of fruits on the left and inflorescence on the right of Medusa's head
Detail of fruits on the left (Photo by Johan Viljoen) and inflorescence on the right (Photo by Joey Santore) of Medusa’s head

These tuberculated branches are green to grayish and essential for photosynthesis, since the plant is largely devoid of true leaves. The small leaves of the Medusa’s Head exhibit a rapidly deciduous behavior, falling off soon after emergence and can be observed at the tip of the growing branches. They are succulent, with a linear, acute or obtuse shape, and measure up to 0.2 inches (5 mm) in length. They are green, but can acquire reddish tones under full sun.

Its curious inflorescences are of the cyathium type, a specialized form found in the genus Euphorbia. They arise in clusters in the axils of the tubercles at the ends of the branches. Each cyathium of the Medusa’s Head is surrounded by 5 to 7 small bracts that harden and persist, forming a cup-shaped involucre. The cyathia are 0.5 inches (12 mm) in diameter, with bright green nectariferous glands, surrounded by white toothed processes that adorn the male flowers and the central female flower with an elongated pedicel. The ovary is sessile and bluntly lobed.

An interesting fact is that only plants originating from seeds form the characteristic caudex, although the species can be propagated by cuttings. Plants propagated by cutting acquire a curious aspect, without the typical radial symmetry and globular base of seed-originated plants. The initial cutting becomes a cylindrical or apex-enlarged stem, from which it branches out, emitting a set of elongated, species-typical branches.

Euphorbia caput-medusae
Plant originating from cuttings on the left (Photo by Leonora Enking). Plant with radial symmetry with branches originating from the caudex, from seed, on the right (Photo by Linde Muller).

In decoration and landscaping, the appearance of the Medusa’s Head is undeniably its most striking attribute. With its succulent, serpentine branches, this plant adds a sculptural and dramatic dimension to any space. The contrast between the bluish-green of the branches and the subtle white of the flowers, when present, offers a visual spectacle that captivates viewers. Due to its unique shape and structure, the Euphorbia caput-medusae is an excellent choice for rock gardens, succulent beds, and as a centerpiece in plant arrangements. Its ability to tolerate drought conditions makes it an ideal candidate for xerophilous or low-maintenance gardens, where water conservation is a priority.

Cascading plant, among rocks.
Cascading plant, among rocks. Photo by Bernard Dupont

In rock gardens, the Medusa’s Head can be planted in such a way that its caudex is partially buried and its branches spread among the stones, creating an intriguing effect. In succulent beds and arrangements, it can be combined with other species of complementary habits and colors to create visual contrasts. Due to its sculptural form, the Euphorbia caput-medusae serves well in isolated cultivations especially in hanging baskets and cylindrical, conical, and “head”-shaped pots. In this way, it attracts the eye and becomes a focal point, especially when positioned in prominent locations, such as house entrances, staircases, patios, or balconies.

It’s important to note, despite its playful appearance, its milky sap is irritating and toxic, which should be considered when positioning the plant in areas frequented by children and pets.

The Medusa’s Head is well adapted to full sun, which contributes to its healthy development and flowering. However, it can tolerate partial shade, especially in hot climate regions. Plants accustomed to shade should be gradually acclimatized to full sun to prevent sunburn. It prefers a well-aerated substrate, composed mainly of inorganic materials like sand, crushed tiles or bricks, expanded clay, and crushed stone, with a small addition of peat. This substrate promotes effective drainage and aeration, essential for root health and rot prevention.

During the active growth period, the Euphorbia caput-medusae should be watered regularly, allowing the soil to dry completely between waterings. It’s important to avoid waterlogging, especially during winter, when the plant’s metabolism slows down, and the need for water decreases significantly. However, it’s worth noting that since it originates from regions with rainy winters, it has a higher tolerance to moisture in the winter compared to other succulents.

A balanced fertilizer, specially formulated for cacti and succulents, should be applied during spring and summer. The fertilizer should be rich in potassium and include all the necessary micronutrients and trace elements for healthy plant development. Being native to subtropical regions, the Euphorbia caput-medusae has some resistance to cold, being able to tolerate temperatures up to approximately 21°F (-6°C). However, it’s advisable to protect it from frost to avoid damage. It shows tolerance to salinity, making it suitable for cultivation in coastal regions. Pruning is not generally necessary, and if done improperly, can mischaracterize it. Use sparingly, with the aim of removing damaged branches or those afflicted by diseases. It’s crucial to handle the plant carefully due to its toxic latex, which can cause skin and eye irritation. The use of gloves and protective eyewear is recommended during handling.

Medusa's Head in a pot.
Medusa’s Head in a pot. The caudex was elevated to highlight its beauty. Photo by Calimecita

Unlike many other succulents, propagating Euphorbia caput-medusae through cuttings may not result in perfect plants, with the typical Medusa’s Head shape. When a cutting is taken from the plant, it tends to develop a set of branches at the apex instead of forming a new typical globular caudex. These lateral branches grow irregularly, resulting in a plant without the original appearance. This behavior means that, while propagation by cuttings is technically viable, it will produce a plant different from what is expected. To propagate by cuttings, cut the branches, drying the exuding latex with paper towels. These cuttings should be left to dry and heal for a few days before planting to reduce the risk of rot.

To achieve the true Medusa’s Head shape, however, seed propagation is preferable. Seeds should be sown in a well-drained substrate and kept moist in a warm environment until complete germination, being gradually acclimated after this period. Plants grown from seeds develop the characteristic caudex of the species.

About Raquel Patro

Raquel Patro is a landscaper and founder of the Since 2006, she has been developing specialized content on plants and gardens, as she believes that everyone, whether amateurs or professionals, should have access to quality content. As a geek, she likes books, science fiction and technology.