Oreocereus hempelianus

Scientific Name

Oreocereus hempelianus (Gürke) D.R.Hunt

Synonym(s)

Arequipa hempeliana, Arequipiopsis hempeliana, Echinocactus hempelianus, Show more

Scientific Classification

Family: Cactaceae
Subfamily: Cactoideae
Tribe: Trichocereeae
Genus: Oreocereus

Origin

This species is native to the mountains of southern Peru and northern Chile. It grows in rocky and sandy soils at elevations from 7,880 to 12,800 feet (2,400 to 3,900 m).

Description

Oreocereus hempelianus, also known as Arequipa hempeliana, is an attractive cactus with short cylindrical stems with 10 to 20 ribs and quite variable spination. The stems are greyish-green, erect or decumbent, and grow to 16 inches (40 cm) long and 6 inches (15 cm) in diameter, solitary or forming clumps. Spines are initially yellow to reddish and become dull grey with age. Each areole bears 1 to 10 flexible, often curved, up to 2 inches (5 cm) long central spines and 8 to 30 needle- to bristle-like, up to 1.2 inches (3 cm) long radial spines. Flowers are scarlet to purplish-red and appear at the apex of the stems in spring. They are tubular, slightly curved, up to 3 inches (7.5 cm) long, and up to 1.4 inches (3.5 cm) in diameter. Fruits are egg-shaped to barrel-shaped, yellowish, up to 1 inch (2.5 cm) in diameter, and contain tiny black seeds.

Etymology

The specific epithet "hempelianus (hem-pel-ee-AH-nus) honors George Hempel (1847-1904), a German businessman, politician, and cactus collector.

Oreocereus hempelianus in bloom — In habitat, Cobija, Camarones, Chile. Derivative of a photo by Andres Puiggros. Used under CC BY-NC 4.0. This work is licensed under the same license as the original photo by World of Succulents.

How to Grow and Care for Oreocereus hempelianus

Light: This cactus likes full sun. It can handle partial shade but thrives in direct sunlight during the summer. A sunny window is a good spot to grow O. hempelianus indoors. Rotate the pot a quarter turn every week or two to encourage balanced growth. If possible, get your cactus outdoors from spring to fall.

Soil: O. hempelianus does not like to have "wet feet" and needs to be grown in well-draining soil. Use commercial soil mixes for cacti or make your own mix.

Hardiness: During the active growth period, this cactus likes warm temperatures, while in winter, it likes cooler temperatures. O. hempelianus can withstand temperatures as low as 20 °F (-6.7 °C). USDA Plant Hardiness Zones 9a to 11b, 20 to 50 °F (-6.7 to 10 °C).

Watering: From spring to fall, water thoroughly, but allow the soil to dry out before watering again. With the arrival of fall, gradually reduce the watering frequency. During the winter, when O. hempelianus is dormant, give it just enough water to prevent shrinking.

Fertilizing: During its growing season, this cactus likes regular fertilizing. A balanced, water-soluble fertilizer, diluted to 1/4 strength, can be added to the water for each watering. A 10-10-10 fertilizer is ideal. Instead of making a solution of water and fertilizer, there are also dry fertilizers. Do not fertilize during the winter.

Repotting: While O. hempelianus is young, it is recommended to repot each year in early spring. Once it matures, repot when your cactus is outgrowing its pot.

Propagation: Using stem cuttings is the easiest method to propagate O. hempelianus because seed propagation is a slow process. Take cuttings during the growing season of the cuctus. Spring and summer is the best time to sow the seeds.

Learn more at How to Grow and Care for Cereus.

Toxicity of Oreocereus hempelianus

O. hempelianus is non-toxic to humans or animals.