Origin and Habitat: Mexico (Tamaulipas, Queretaro).

• Stenocactus caespitosus (Backeb.)
• Echinofossulocactus caespitosus Backeb.

• Stenocactus obvallatus (DC.) A.Berger
• Brittonrosea obvallata (DC.) Speg.
• Cactus obvallatus Moc. & Sessé ex DC.
• Echinocactus obvallatus DC.
• Echinocactus obvallatus var. lancifer Schelle
• Echinocactus obvallatus var. pluricostatus Monv.
• Echinocactus obvallatus var. spinosior Salm-Dyck
• Echinofossulocactus crispatus f. obvallatus (DC.) P.V.Heath
• Echinofossulocactus obvallatus (DC.) Lawr. in Loudon
• Efossus obvallatus (DC.) Orcutt
• Stenocactus caespitosus (Backeb.)
• Echinofossulocactus caespitosus Backeb.
• Stenocactus pentacanthus A.Berger
• Brittonrosea pentacantha (Lem.) Speg.
• Echinocactus anfractuosus var. pentacanthus (Lem.) Salm-Dyck
• Echinocactus pentacanthus Lem.
• Echinofossulocactus crispatus f. pentacanthus (Lem.) P.V.Heath
• Echinofossulocactus pentacanthus (Lem.) Britton & Rose
• Efossus pentacanthus (Lem.) Orcutt

Description: It is a globular cactus which became elongate when old , even though usually solitary this species is one of the few members of the genus that can put forth basal shoots. It does so as a young plant, becoming sometime densely branched. Stems rather small up to 10 cm in diameter, 10 (20) cm tall with about 27 corrugated, sharp-edged ribs, swollen where the areoles grow. The latter are round and thickly felted around the apex, later becoming almost bare.
Spines: there are 3 major spines on the upper part of the areoles: two are conical and curved upward while the central spine is flattened, yellowish or pinkish , about 2 (4) cm long and 2 (4) mm wide. On the older part of the plant there are four small white radial spines, and sometime another central spine appears below the others, pointing downward; it is curved, flat, and the same length as the upper central spine.
Flowers: 1-2 cm long can be up to 3-4cm in diameter. It has white or pale yellow flowers with pink mid-veins and a greenish base.. The plants known as Stenocactus pentacanthusSN|6285]]SN|6296]] have long lasting bluish flowers in early spring.
Remarks: S. caespitosus nowadays is not considered a distinct species or variety but only one of the variable phenotypes of the clinal species Stenocactus obvallatusSN|6296]]SN|6285]].

Cultivation and Propagation: Easy to to care and flower. It needs regular cacti soil with good drainage, allow to dry between watering. It should not be watered at all in winter.
Propagation: Seeds (usually) or but, since it tillers early, it is simpler to use shoots.
Exposure: It likes strong sunshine but is tolerant and do well with light shade during the hot Summer months.
Frost Tolerance: does not tolerate intense or prolonged cold (hardy to -5°C if kept dry)