Origin and Habitat: Trujillo, Peru. Altitude: 800-1000 metres over sea level.

• Melocactus trujilloensis Rauh & Backeb. in Backeb.

• Melocactus peruvianus Vaupel
• Cactus townsendii Britton & Rose
• Melocactus fortalezensis Rauh & Backeb. in Backeb.
• Melocactus huallancaensis Rauh & Backeb.
• Melocactus jansenianus Backeb.
• Cactus jansenianus (Backeb.) Borg
• Melocactus peruvianus var. amstutziae Rauh & Backeb. in Rauh
• Melocactus amstutziae Rauh & Backeb. in Backeb.
• Melocactus peruvianus var. canetensis Rauh & Backeb. in Rauh
• Melocactus peruvianus var. lurinensis Rauh & Backeb. in Rauh
• Melocactus trujilloensis Rauh & Backeb. in Backeb.
• Melocactus trujilloensis var. schoenii Rauh & Backeb. in Backeb.
• Melocactus unguispinus Backeb.

Description: This is probably one of the many geographical forms of the extremely variable Vaupel's Melocactus peruvianusSN|12607]]SN|12607]].
Melocactus peruvianusSN|12607]]SN|12607]] is a small solitary globose cactus.
Stem: Erected, depressed globose to pyramidal or short cylindrical,13-20 cm tall and in diameter, glaucous green.
Areoles: up to 5 x 10 mm in size, roundish-elongated with brown felt.
Ribs: 10-15.
Spines: Extremely variable yellowish to dark brown or black turning grey as they age
Central spines: Missing or 1 to 4 up to 6 cm long.
Radial spines: 4-15 up to 2-3(-6) cm long, 0,5-1 mm in diameter, straight to strongly curved, sometimes interlaced and pectinate and more or less angular and keeled above.
Cephalium: Apical, often small, 5-15 cm tall, 8-10 cm in diameter with white wool and aboundant reddish-brown bristles.
Flowers: Actinomorphic, tubular, pink to red, emerging 2-3 cm over the cephalium, corolla 5-15 mm in diameter, tepals about 15 of which: petaloids ligulate-apiculate 5-6 mm long, 0,75-1 mm wide and sepaloid lanceolate-apiculate 3-6 mm long, 1-2 mm wide; tube 5 mm long, 3-4 mm wide; nectar chamber 2-4 mm long, 2 mm in diameter; Stamens about 90, 2-4 mm long, filaments 1-3 mm long, 0,1 mm in diameter, anther creamy-white, 1 mm long, 0,5 mm in diameter; Stigma 4-12 mm long with 5 green lobes;
Fruit: Red at the tip, ellipsoidal to pear shaped, 18 mm long, 6-7 mm in diameter with persisting flowers remnants, pulp whitish with 60-120 seeds.
Seeds: Ovoidal-reniform, 1-1,1 mm long, 0,8-0,9 mm in diameter, dark brown to black,

Cultivation and Propagation: These cacti are not the easiest things to grow and aren’t plants for beginners. Melocactus trujillensis 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.