Origin and Habitat: Garden origin (Nursery produced). The wild species occurs over a considerable range from Guanajuato to Querétaro, San Luis Potosí and Hidalgo (Meztitlan, Toliman and Jacala) in Eastern central Mexico.

• Ferocactus glaucescens cv. Split Rock hort.
• Ferocactus glaucescens f. monstruosus hort.

• Ferocactus glaucescens (DC.) Britton & Rose
• Bisnaga glaucescens DC., Orcutt
• Echinocactus glaucescens DC.
• Echinocactus pfeifferi Zucc. in Pfeiff.
• Ferocactus pfeifferi (Zucc. & sine ref.) Backeb.
• Ferocactus glaucescens f. cristata
• Ferocactus glaucescens f. nudus cristatus monstuosus clone A
• Ferocactus glaucescens f. nudus cristatus monstuosus clone B
• Ferocactus glaucescens f. nudus cristatus
• Ferocactus glaucescens f. nudus
• Ferocactus glaucescens f. inermis hort.
• Ferocactus glaucescens var. unispinus
• Ferocactus glaucescens f. variegatum hort.

• Ferocactus glaucescens cv. Split Rock hort.
• Ferocactus glaucescens f. monstruosus hort.

Description: The Ferocactus glaucescensSN|1532]]SN|1532]] cv. Split Rock (a.k.a. forma mostruosa nuda) is a strange solitary, barrel cactus that forms a beautiful stems, that looks like an old weathered rock.
Stem: The younger plants are very similar to the common Ferocactus glaucescensSN|1532]]SN|1532]] f. nudus with spineless globular depressed glaucous grey stems, but the epidermis of this cultivars starts soon to split open assuming the appearance of a rock surface.
and in a few years the plant take on a completely different appearance. The stem slowly grows up to 55 cm in height, 50 cm in diameter and may become shortly columnar as it ages.
Ribs: 11 to 15 , but very irregular often fused together, suddenly broken or scratched with thin grooves.
Areoles: Light orangish or greyish, long and often fused one to each other.
Spines: Absent.
Flowers: Lemon yellow, funnel-shaped, 3-4 cm in diameter. The tepals are oblong, lanceolate, silky, shining; the margins are finely fringed. Stamen, style and stigma are yellow. Stigma lobes 12-15.
Blooming season: Late spring and summer. The flowers last a very long time. The plants start flowering when about 13 cm in diameter.
Fruits: White, 2 cm long with the remnants of the flowers attached.
Remarks: Do not confuse this odd cultivar with the common Ferocactus glaucescensSN|1532]]SN|1532]] f. nudus which is a completely different cultivar that is superficially similar only when very young. The unique charm of this plant will be revealed as it ages.

Cultivation and Propagation: Plants are slow growing to start but are easy to grow and require little care once they have reached a nice flowering size. F. glaucescens is suited for any rich, well drained soil in full sun throughout the year. Pot culture: grow best in a fairly roomy, well-drained container filled with a porous cactus soil mixture that doesn't contain too much humus. To ensure robust plants water and fertilize during the aestival growth cycle, this plant need plenty of water (indicatively: about once a week) But it is necessary to avoid wetting the bodies of these plants while they are in sunlight. A wet cactus in the sun light can cause sun burning, which can lead to scars or even fungal infections and death. In winter keep completely dry at 10°C. This usually aids in maintaining a healthier plant, but it can tolerate sporadic light frost.
Propagation: Seeds are the typical way of reproducing. These cacti will easily grow from seeds and some from cuttings.