: Veracruz, Mexico
Altitude range: 0-400 metres above sea level.
Habitat and ecology: Melocactus delessertianusSN|17733]]SN|17733]] used to be common but now is almost extinct because of overcollecting by horticulturists. It grows together with Mammillaria erinaceaSN|26072]]SN|26072]], Acanthocereus pentagonusSN|4326]]SN|4326]], Opuntia puberula, Selenicereus pteranthusSN|7536]]SN|7536]], Nopalea dejecta and Bromelia pinguin.

• Melocactus delessertianus Lem.

• Melocactus curvispinus Pfeiff.
• Melocactus crassicostatus Lem.
• Melocactus obtusipetalus var. crassicostatus (Lem.) Lem. ex Miq.
• Melocactus curvispinus subs. obtusipetalus (Lem.) Xhonneux & Fern.Alonso
• Cactus obtusipetalus (Lem.) Britton & Rose
• Melocactus obtusipetalus Lem.
• Melocactus delessertianus Lem.
• Melocactus guatemalensis Gürke & Eichlam
• Melocactus guitartii León
• Melocactus holguinensis Areces
• Melocactus humilis Suringar
• Melocactus jakusii Mészáros
• Melocactus maxonii (Rose) Gürke
• Cactus maxonii Rose
• Melocactus ruestii subs. maxonii (Rose) Elizondo
• Melocactus oaxacensis (Britton & Rose) Backeb.
• Cactus oaxacensis Britton & Rose
• Melocactus ruestii subs. oaxacensis (Britton & Rose) Elizondo
• Melocactus ruestii K.Schum.
• Cactus ruestii (K.Schum.) Britton & Rose
• Melocactus brongnartii Hildm. ex Rüst non Lem.
• Melocactus ruestii subs. centalapensis Elizondo
• Melocactus ruestii subs. cintalapensis Elizondo
• Melocactus ruestii subs. sanctae-rosae (L.D.Gómez) Elizondo
• Melocactus maxonii var. sanctae-rosae L.D.Gómez
• Melocactus salvador L.Murillo
• Cactus salvador (L.Murillo) Britton & Rose

• Melocactus curvispinus subs. caesius (H.L.Wendl.) N.P.Taylor
• Cactus caesius (H.L.Wendl.) Britton & Rose
• Melocactus caesius H.L.Wendl. ex Miq.
• Melocactus curvispinus f. caesius (H.L.Wendl.) N.P.Taylor

• Melocactus curvispinus subs. dawsonii (Bravo) N.P.Taylor
• Melocactus dawsonii Bravo

• Melocactus curvispinus subs. koolwijkianus (Suringar) G.Thomson
• Melocactus koolwijkianus Suringar
• Melocactus koolwijkianus var. adustus Suringar

• Melocactus curvispinus subs. lobelii (Suringar) Fern.Alonso & Xhonneux
• Melocactus curvispinus f. lobelii (Suringar) N.P.Taylor
• Melocactus lobelii Suringar
• Melocactus cephalenoplus Lem.
• Melocactus griseus H.L.Wendl. ex Miq.
• Melocactus caesius var. griseus (H.L.Wendl. ex Miq.) Förster

• Melocactus curvispinus subs. loboguerreroi (Cárdenas) Fern.Alonso & Xhonneux
• Melocactus loboguerreroi Cárdenas

: Melocactus delessertianusSN|17733]]SN|17733]], Lemaire (Hort. Univ. 1 : 225. 1839), has been described from Mexico (Veracruz) which may or may not be this plant. It was described as slightly depressed, about 10 cm. high with 12 to 15 ribs. Radial spines 8 or 9, centrals 2. The flowers and fruit unknown.
The characteristics of Melocactus delessertianusSN|17710]]SN|17733]], appear to fall within the natural variation of Melocactus curvispinusSN|17733]]SN|17710]]. Melocactus delessertianusSN|17733]]SN|17733]] is not accepted by botanists that treat it as synonym.

: Major references and further lectures
1) Britton, N. L., and J. N. Rose. 1922. “The Cactaceae.” Vol. 3. Canegie Institute: Washington.
2) Miguel J. Chazaro "Miscellaneous papers on the flora of Veracruz, Mexico" University of Wisconsin-Madison, 1989

: These cacti are not the easiest things to grow and aren’t plants for beginners. It grows from April to October, it can’t endure long stretches of total dryness, and also too much water will rot it, as its weak root systems tends to be inefficient at sucking up water from wet soil. Nonetheless, again as a result of their tropical origins, they need a fair amount of water, but allow the soil to dry quite a bit before watering again. Melocactus rests from October to April but can’t stand cold, or even fairly cool temperatures, so is indispensable to keep it above 8-12°C at all times, severe damage or death occurring at temperatures that the great majority of cacti wouldn’t mind in the least and prefer more frequent water in winter than other cacti, say once a month. Do not feed in winter.
The root system is weak and generally resents being repotted and can take a long time to re-establish. The soil mix should be very quick draining, prefers very bright light, not as much as the most arid growing cacti, but plenty nonetheless.
Propagation: Exclusively by Seeds. Sow in February-march in a light, sandy, porous soil. Cover germinating tray with glass to prevent seed from drying out. Germination is most successful at a temperature of 18 to 22° C.