Gymnocalycium pflanzii (Vaupel) Werderm. 

🌱 Morphology
 Flattened and plump… Gymnocalycium globoso of relatively fast growth, generally solitary at first, although with age it can produce offsets. The body is globose-flattened, yellowish-green, olive green or grayish-green in color, and reaches approximately 6–8 cm in height and up to 15 cm in diameter. It has only 8–10 ribs, thick and well-marked, divided into rounded polygonal tubercles. The areoles are elongated and oval, with initially yellowish-cream wool. It develops 6–9 radial spines, robust, rigid and characteristically curved backwards, in addition to a generally short central spine. The spines can be pinkish-brown or whitish-brown, with a darker tip.

These characteristics allow it to be distinguished from Gymnocalycium saglionis, much larger and with 15–30 or more low and wide ribs, larger and more elongated areoles and generally longer spines. In G. pflanzii, the lower number of ribs and the strongly recurved radial spines are good clues for its identification.

🌍 Distribution, habitat and family
It has a wide distribution in Bolivia, Paraguay and northern Argentina, where it grows on sandy plains and rocky outcrops, approximately between 500 and 2,000 m above sea level. It mainly inhabits dry and seasonally arid environments, often among low vegetation that provides some protection from the most intense sunlight. The species is highly variable and several subspecies are currently recognized.
Family Cactaceae · Subfamily Cactoideae · Tribe Cereeae 

❄️ Temperature · USDA Zone 8a
Tolerates minimum temperatures of up to −12 ºC for short periods and with completely dry substrate. Although it comes from relatively warm regions, some populations live at a sufficient altitude to withstand dry cold spells. In cultivation, the combination of cold and moisture should be especially avoided.

☀️ Lighting
Needs plenty of light. It can be grown with gentle direct sun, but in very intense summers it is advisable to provide light protection during the middle hours. Adequate lighting promotes compact spination and can produce bronzed or purple hues on the epidermis. PAR radiation of 20–30 mol·m⁻²·day⁻¹ (DLI) is recommended.

💧 Growth cycle and watering
Winter dormancy. During active growth, it is recommended to water abundantly and let the substrate dry out completely before the next watering. In autumn, the inputs are gradually reduced to keep it dry during the winter. A very well-draining substrate is essential to avoid root problems.

🌸 Flowering
The flowers emerge near the apex and are campanulate to infundibuliform, with a short floral tube, from pinkish-white to salmon pink in color, and can reach about 5 cm in length and diameter. The throat has a characteristic carmine to purple-pink hue, while the style is also reddish and the anthers are yellow. The flowers last several days and can appear successively during the growing season.

The flower also constitutes one of the best characteristics to separate it from G. saglionis: in pflanzii the flower is more clearly campanulate, with a red throat and short tube; in saglionis it is urceolate, with no tube or a very short one and without the characteristic carmine throat, and its stamens are whitish or yellowish instead of reddish. G. pflanziican flower relatively young and produce several flowers during the season.

🌿 Nutrition
During active growth, Desert CHOICE® Cactaceae NPK (Ca-Mg) 4-4-7 (4-4) is recommended once a month along 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 and with the substrate activated with mycorrhizal fungi and biofungicides.