Growth form and former names
The young stem is spherical and elongates with age. Areoles develop on dark green ribs, bearing strong, usually red spines and fine white bristles. The RHS gives a height of up to around 3 m for wild plants. Potted specimens usually remain much smaller. Red or yellow flowers appear in a ring near the tip, in early summer according to the horticultural description. [1-WWW]
POWO accepts Ferocactus pilosus (also F. stainesii and F. pringlei in older literature). Britton and Rose described F. pringlei as a clump-forming plant. Its yellow fruits opened through a hole at the base, and its brownish seeds were around 1.5 mm long. These features describe material in the former circumscription of F. pringlei, now included in F. pilosus. [2-WWW] [Britton and Rose 1922, p. 125–126]
Range and material from the southern Chihuahuan Desert
Plants of the World Online gives northeastern Mexico, with a range reaching Jalisco, and the desert and dry scrub biome. The microbiome study examined a population from Guadalcázar in San Luis Potosí. Closed, mature fruits were collected during the rainy season in 2018. After extraction, seeds from at least ten plants were pooled into one sample, from which surface and internal microorganisms were described. [2-WWW] [Mascot-Gómez et al. 2021]
Prior wetting changes germination
Contreras-Quiroz and colleagues compared dry F. pilosus seeds with seeds subjected to wetting and drying cycles. The best response followed three successive cycles, each comprising 24 h of hydration and five days of drying. Each treatment had five dishes of ten seeds. After preparation, germination was observed for 30 days, with 12 h of light at 30°C and 12 h of darkness at 16°C. Three cycles increased the germination percentage and shortened t₅₀ from 11.8 to 5.8 days. The parameter t₅₀ meant the time taken for half of the seeds that ultimately germinated in a treatment to do so. [Contreras-Quiroz et al. 2016, metody; tabele 1–2]
The result documents hydration memory at the level of seed responses. The detailed 2014 study of RNA and proteins concerned different material, present-day F. townsendianus (called F. peninsulae var. townsendianus in the publication). This is the species described in the article on molecular traces of prior wetting. [López-Urrutia et al. 2014] [2-WWW]
The inside and surface of a seed
In the 16S rRNA sequence study of F. pilosus, reads assigned to Stenotrophomonas dominated inside the seeds, while those assigned to Paenibacillus dominated on the surface. Fourteen bacterial isolates were cultured, eight from the surface and six from inside. Each showed at least one laboratory-tested trait associated with potential support for plant growth. Sample composition and an isolate's ability to act on culture medium are two separate results. [Mascot-Gómez et al. 2021, pp. 4–5]
Surface strains of Enterobacter and Achromobacter produced siderophores, compounds that bind iron. This property can affect the availability of the element to different microbiome members. The study did not determine the effect of adding them on F. pilosus seedling growth. The functional seed study was conducted in Echinocactus platyacanthus. The distinction between microbial community composition and its experimentally confirmed influence on the plant is explored in the article on the seed microbiome. [Mascot-Gómez et al. 2021, p. 4, 8–9]
Cultivation and sowing
The RHS recommends abundant sun and a free-draining cactus substrate. Watering is moderate during growth, and the plant remains almost dry in winter. The horticultural profile gives propagation from seeds sown in spring at 21°C. British class H2 means protection from freezing is required. In Poland, the main cultivation method therefore remains a container moved to a protected room or greenhouse. [1-WWW]
Among problems, the RHS lists mealybugs and rots caused by excessive watering. A separate article on flower-bud composition presents laboratory studies of material called cabuches and its processing. The biochemistry of this material has its own account in the applications section. [1-WWW]
Related articles
Materials from the author's archive
The species also appears in Konrad Szychowski's private material archive. [Cactáceas y Suculentas Mexicanas 1959, file p. 24]
Synonyms and names in the literature
Echinocactus pilosus · Ferocactus stainesii · Ferocactus pringlei · Ferocactus pilifer · Echinocactus pringlei · Ferocactus stainesii var. pilosus · Ferocactus stainesii var. pringlei [2-WWW]