Hamatocactus hamatacanthus (Muehlenpf.) F.M.Knuth

🌱 Morphology
Globose to ovoid cactus that becomes elongated with age, acquiring a short-cylindrical form; it is generally solitary, although it can produce basal offsets. The stem is dark green, approximately 30–60 cm long and 20–30 cm in diameter, with some specimens reaching larger dimensions. It typically has 13 ribs, which are thick, markedly wavy, and sometimes deeply tuberculate. The areoles are elongated, woolly, and may feature nectar glands. Its most striking feature is its spination: it develops 8–12 radial spines, accompanied by 1–4 central spines; the lowest one is particularly long, flattened, and strongly hooked. Young spines may show reddish or reddish-brown tones and evolve toward straw, horny, or grayish shades.

🌍 Distribution, habitat, and family
It is distributed throughout the southern United States and northern and central Mexico, from southeastern New Mexico and Texas to Chihuahua, Coahuila, Durango, Nuevo León, San Luis Potosí, Tamaulipas, Zacatecas, and other areas of central Mexico. It inhabits mainly the Chihuahuan Desert, in mineral soils, plains, terraces, rocky slopes, and rock crevices, frequently partially protected among shrubs. It is found from low elevations up to approximately 2000 m. It belongs to the Cactaceae family, subfamily Cactoideae.

The name Hamatocactus refers precisely to its hook-shaped central spines. Although it was treated within this genus for a long time, in much of contemporary taxonomy it has been included in Ferocactus.

❄️ Temperature · USDA Zone 8b
It tolerates minimum temperatures of down to −7 ºC when kept dry and for well-acclimatized specimens. It can withstand moderate frosts, but must be kept completely dry during periods of intense cold.

☀️ Lighting
It requires plenty of light and direct sun to maintain compact growth and develop its characteristic hooked spination. Insufficient lighting encourages stem elongation and reduces the color intensity of the spines. As a general guideline during active growth, a DLI PAR of 20–30 mol·m⁻²·day⁻¹ is recommended.

💧 Growth cycle and watering
Winter rest. During the cold period, it should be kept dry. With rising temperatures in spring, growth begins and it can be watered abundantly but infrequently, allowing the substrate to dry out completely between waterings. It is advisable to maximize drainage, as excess water can cause cracks in the epidermis and root problems.

🌸 Flowering
It produces infundibuliform (funnel-shaped), fragrant flowers approximately 6–7 cm long, which appear in the apical area during the summer. They are generally yellow, often with the center or throat sometimes reddish, and open during the day. The fruits are small, fleshy, globose or ovoid, green in color, which can turn into yellowish or reddish tones, and contain black seeds.

🌿 Nutrition
During the active growth period, a fertilizer with a high content of assimilable calcium and low nitrogen levels, such as Desert CHOICE® Cactaceae, is recommended, applied once a month during 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 and biofungicides.