Mammillaria polythele f. inermis | Spineless Amethyst Crown
€7,95
Mammillaria polythele Mart.
🌱 Morphology
A spineless cultivar of this cactus with a globose to cylindrical body, generally solitary although it may branch with age, bluish-green in color and up to about 40–50 cm in height and 8–10 cm in diameter. The tubercles are large, conical or pyramidal, arranged in a spiral, with axils provided with white wool. Young plants usually have only 2 spines, while with age they can develop 3–7 or more, brown to reddish in color, up to 2.5 cm long. Some cultivated forms are practically unarmed, like this cultivar.
🌍 Distribution, habitat and family
Endemic to Mexico, mainly Guanajuato, Hidalgo and Querétaro, with populations also in other states depending on the taxonomic treatment. It lives at approximately 1,700 to 2,400 m, in xerophilous scrublands, rocky slopes and open oak forests, frequently among dense vegetation and in partial shade, on mineral and generally calcareous soils. It belongs to the Cactaceae family, subfamily Cactoideae, tribe Cacteae. Joël Lodé maintains Mammillaria polythele as an independent species and also recognizes the subspecies durispina and obconella.
❄️ Temperature · USDA Zone 9a
It tolerates minimum temperatures of up to −5 ºC when dry and in well-acclimated specimens. Although it comes from high altitudes, resistance depends a lot on the resting state and keeping the substrate completely dry during cold weather.
☀️ Lighting
It needs plenty of light, but it should not be confused with a strictly desert cactus: in nature it also grows protected by vegetation. Mild direct sun or very intense light is recommended, with progressive acclimation and slight protection during episodes of extreme heat. During active growth, an approximate DLI PAR of 20–30 mol·m⁻²·day⁻¹.
💧 Growth cycle and watering
Winter rest. Keep practically dry during winter. In spring and summer, a deep watering is recommended when the substrate is completely dry, then allowing it to dry out completely again. The cold and dry period is especially important to induce good flowering.
🌸 Flowering
It can bloom from about 3–4 years from seed, when it reaches sufficient size and has correctly undergone its winter rest. It produces small pink, magenta to purple-red flowers, approximately 1 cm long, arranged in a crown around the apex.
The documented phenology is especially interesting: in a population studied in Jalisco, buds were observed in June and flowering from June to October, followed by fruiting in January. Therefore, it presents prolonged flowering within the same season, consistent with successive flowering pulses; however, a fixed number of 2–3 waves has not been documented with sufficient precision, so it should not be stated that it necessarily produces three pulses each year. The flowers are hermaphroditic and diurnal.
🌿 Nutrition
During the active growth period, a fertilizer with a high content of assimilable calcium and low levels of nitrogen is recommended, such as Desert CHOICE® Cactaceae, applied once a month when watering. Before flowering, it can be supplemented with Desert CHOICE® Flowering.
This is an inimitable xerophyte grown in Madrid in a technical square pot with the substrate activated with mycorrhizal fungi
📏 The sizes of our basic collection xerophytes are as follows:
S -> 9cm x 9cm
M-> 14cm x 14 cm
L->16cm x 16 cm
* As this is an online purchase, the appearance of the sent specimen may vary slightly from the product image. The dimensions of the plant are specified in the photo description, but this may also vary slightly, because it is a living being! Each of the plants at Desert CITY has unique characteristics.

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