Pack Size: 20, 100, 300
Year: 2026
Accepted Scientific Name: Gymnocalycium eurypleurum F.Ritter
Origin and Habitat:
Gymnocalycium eurypleurum is a distinctive cactus species native to northern Paraguay, particularly the Alto Paraguay region of the Gran Chaco. It inhabits seasonally dry subtropical forests, open woodlands, and areas with clay-rich and mineral soils, often growing among sparse shrubs and grasses. These environments experience hot summers, mild winters, and seasonal rainfall followed by extended dry periods. Plants are frequently found in partially shaded locations beneath surrounding vegetation, which provides protection from intense sunlight. The species is adapted to warm conditions, seasonal moisture, and well-drained growing sites. Its restricted natural distribution and unusual appearance make it particularly desirable among specialist cactus collectors.
Description:
Gymnocalycium eurypleurum is a slow-growing, predominantly solitary cactus characterized by its flattened, globular shape and distinctive olive-green to brownish-green epidermis, occasionally developing bronze or purplish tones under strong sunlight. Mature plants typically reach approximately 1.5–3" tall and 3–5" in diameter. The body develops 7–12 broad, low ribs divided into slightly raised, chin-like tubercles. Each areole produces approximately 4–7 stout, straight to slightly curved radial spines, ranging from reddish-brown to grey-brown and measuring approximately 0.5–1.2" long. Central spines are generally absent or occasionally present. Mature plants produce attractive, funnel-shaped flowers approximately 1–1.5" across, displaying creamy white to pale pink petals, sometimes with delicate pinkish central markings. Flowers emerge near the crown during spring and summer, followed by small, barrel-shaped fruits ranging from whitish to purplish tones. Its compact form, broad ribs, and contrasting spination make it an appealing addition to specialist cactus collections.
Cultivation:
Zone: 9–11; protect from frost and excessive winter moisture.
Temperature: Optimal growth at 20–30 °C. Maintain winter temperatures above 8–10 °C for reliable cultivation.
Growth Rate: Slow, gradually developing a flattened, globular body with broad ribs and prominent spines.
Soil: A fast-draining cactus mixture containing pumice, fine gravel, and a moderate proportion of organic matter. A slightly acidic to neutral growing medium with excellent drainage is recommended.
Watering: Water thoroughly during active growth, allowing the growing medium to dry between waterings. Reduce watering significantly during autumn and keep mostly dry during winter dormancy.
Fertilizing: Apply a diluted, low-nitrogen cactus fertilizer every 2–3 weeks during active growth. Discontinue feeding during winter.
Light: Bright, indirect light to partial sun. Gentle morning sunlight encourages compact growth and healthy flowering. Protect from intense afternoon sunlight, particularly during hot summer weather.
Pests and Diseases: Susceptible to mealybugs, root mealybugs, spider mites, scale insects, and root rot associated with excessive moisture or poorly draining growing media.
Germination Info:
Temperature: 27 °C.
Surface Sown: Yes. Sow seeds on the surface of a fine, sterilized cactus growing medium and press lightly into place without burying deeply.
Germination Time: Approximately 7–28 days under favourable conditions, although some seeds may require longer.
Moisture: Maintain consistent surface moisture and high humidity during germination, avoiding waterlogged conditions.
Light: Bright, indirect light. Avoid direct sunlight on covered seed trays.
After Germination: Gradually increase ventilation as seedlings establish. Maintain moderate moisture until young plants develop stronger root systems and begin producing characteristic ribs and spines.
