Il F. reppenhagenii anche da adulto resta di piccolo diametro ma si allunga molto ed assume una forma colonnare quasi cereoide.

Family: Cactaceae (Cactus Family)

Scientific name: Ferocactus reppenhagenii G. Unger,
Pubblished in: Kakt. And. Sukk., 25 (3): 50., 1974

Origin:  It is found in the states of Colima, Michoacan, Guerrero (while the areas of distribution of the strictly related F. alamosanus in the state of Sonora  is about 1000 km apart... ...a reason to accept the two taxa as different species)

Conservation status: Listed in CITES appendix 2.

Synonyms:

• Ferocactus alamosanus ssp. reppenhagenii (G. Unger) N.P. Taylor
  Pubblished in: Cactaceae Consensus Initiatives 6: 15, 1998
• Echinocactus alamosanus Britton et Rose 1913
• Ferocactus alamosanus var. reppenhagenii
• Parrycactus alamosanus ssp. reppenhagenii
  

(This Taxon belong to a group of six closely allied species. The group is: F. alamosanus, F. pottsii, F. schwarzii, F. reppenhagenii, F. glaucescens, & F. echidne)

Ferocactus reppenhagenii: a mature specimen.

Description:  F. reppenhagenii as old plants are of a small diameter, nearly cereoid growing with usually less than 13 ribs (while F. alamosoanus  are large globular in appearance with many ribs (more than 20).
Stem: Shortly cylindrical up to 30 cm (but usually less) in diameter, 75 to 100 cm tall, occasionally much taller;
Ribs: 12-18 (rarely more than 13) Rounder than in F. alamosoanus.
Areoles: In old plants they are almost connected.
Spines: Needle-like, yellowish and densely intermeshed.
Central spine: 1, sometimes flattened, to 6 cm long;
Radial spines: 8 straw-coloured, 3 to 4 cm long .
Flowers: Greenish yellow, small and narrow 3-4 cm long, 3 cm in diameter the petals are  lanceolate and acute
Fruit: Bright red and not splitting when ripe

Cultivation: It is a summer-growing and pretty easy species thought slow to start. It is suited for any rich, well drained soil in full sun throughout the year.  Water it during the aestival growth cycle (this plant need plenty of water) but be careful not to overwater and also needs to be avoided wetting the body of this plant while it is in sunlight. A wet cactus in the sun light can cause sun burning which can lead to scares or even fungal infections and death.  In winter keep completely dry at 10°C, but can tolerate sporadic light frost. Plant in good conditions will start to  bloom when reach the diameter of only 15-18 cm. It is apt to undergo attacks of red spiders if it is placed near fruit trees.

Propagation: Seeds are the only way of reproducing.

Seed Collecting: Permit fruit to ripen.  Fruit must be significantly overripe before harvesting seed; clean and dry seeds.