Gymnocalycium neuhuberi H.Till & W.Till 

🌱 Morphology
 Small Gymnocalycium, generally solitary, with slow to moderate growth, featuring a globose-flattened body with a matte grey-green epidermis, reaching approximately 5 cm in height and 7 cm in diameter. It develops 9–12 wavy ribs, divided into well-defined tubercles by transverse grooves. The areoles are rounded or oval, measuring about 6–7 mm. It has 9 rigid yellow radial spines, measuring 1.1–2 cm, and young specimens usually have a central spine; with age, up to four central spines may develop, arranged in a cross and slightly longer than the radial spines. The spines can take on dark yellow, orange, or brown tones.

🌍 Distribution, habitat, and family
Species endemic to the province of San Luis, Argentina, known mainly from the surroundings of Suyuque Nuevo and Suyuque Viejo, on the southwestern slopes of the Sierra de San Luis, at approximately 800–1550 m. It grows in arid mountain grasslands, among granite outcrops and scree slopes, in very well-drained soils. Its extremely restricted distribution has led it to be considered Critically Endangered (CR).

Family Cactaceae · Subfamily Cactoideae · Tribe Cereeae 

❄️ Temperature · USDA Zone 7b
Tolerates minimum temperatures of up to −15 ºC when kept completely dry. However, in cultivation, it is recommended to avoid the combination of intense cold and moisture in the substrate.

☀️ Lighting
It requires plenty of light, although in Madrid's climate it is advisable to provide soft direct sunlight or filtered light during the most intense hours of summer. A DLI of 20–30 mol·m⁻²·day⁻¹ promotes compact growth, a well-colored epidermis, and vigorous spines.

💧 Growth cycle and watering
Winter dormancy. Its activity is concentrated mainly from spring to summer. During active growth, it is recommended to water abundantly and allow the substrate to dry out completely before the next watering. In autumn, watering is gradually reduced until it remains completely dry during the winter.

🌸 Flowering
This is one of its most distinctive features. It produces flowers from lilac to pale violet-pink, short-funnel-shaped, measuring approximately 2.7–3.6 cm in length and 2.6–3.4 cm in diameter. They form near the apex from young areoles and may be fragrant. Flowering takes place mainly in late spring and early summer; the flowers may remain open for several days and open especially in the afternoon. 

🌿 Nutrition
During active growth, Desert CHOICE® Cactaceae NPK (Ca-Mg) 4-4-7 (4-4) is recommended once a month with watering. Assimilable calcium promotes the formation of firm tissues and the maintenance of turgidity, while magnesium participates in chlorophyll synthesis. Before flowering, it can be supplemented with Desert CHOICE® Flowering.

🪴 Pot
12x12 cm gourmet black pot

This is an inimitable xerophyte grown in Madrid in a technological square pot with a substrate activated with mycorrhizal fungi and biofungicides.