• Echinocereus roemeri (Muehlenpf.) Rydb.
• Cereus roemeri Muehlenpf.

• Echinocereus fendleri (Engelm.) Rümpler
• Cereus fendleri Engelm.
• Echinocereus fendleri var. kuenzleri (Castetter, P.Pierce & K.H.Schwer.) L.D.Benson
• Echinocereus kuenzleri Castetter, P.Pierce & K.H.Schwer.
• Echinocereus roemeri (Muehlenpf.) Rydb.
• Cereus roemeri Muehlenpf.

• Echinocereus fendleri subs. hempelii (Fobe) W.Blum in W.Blum et al.
• Echinocereus hempelii Fobe
• Echinocereus pseudohempelii hort.

• Echinocereus fendleri subs. rectispinus (Peebles) N.P.Taylor
• Echinocereus fendleri var. rectispinus (Peebles) L.D.Benson
• Echinocereus rectispinus Peebles
• Echinocereus fendleri subs. rectispinus Prescott, Yavapai County, Arizona, USA

Description: The name roemeri has been used to indicate 2 distinct Echinocereus species generating more confusion among cactus fanciers and grower about it than about any other Echinocereus species. Echinocereus roemeri Engelm. ex F.Haage (firstly described as Cereus roemeri by Engelman in 1849)is a synonym of Echinocereus coccineusSN|7140]]SN|7140]]. The other, Echinocereus roemeri(Muehlenpf.) Rydb. (firstly described as Cereus roemeri by Muehlenpf. in 1848) is a homonym and is a synonym of Echinocereus fendleri)

Cultivation and Propagation: It grows rather slowly and is sensitive to over-watering (rot prone). Keep drier and cool in winter. It needs full sun. Very cold resistant, reportedly to -18°C or less (depending on clones), but needs good drainage and protection from excessive moisture in winter and well mulched with gravel chips. It is a fine plant for a rock garden or container, and contrasts well with agaves, yuccas, and low-growing flowering plants. It will show its flowers only provided with an adequate winter rest period.
Propagation: Seeds, can also be grown from cuttings, as it branches from the base.