[2] This plant usually forms a symbiotic relationship with creosote bushes (Larrea tridentata) via mycorrhiza, allowing its thin shoots to lean on them.

[2] The green, slender, cylindrical shoots have a diameter of 0.5 to 1.5 cm (0.20 to 0.59 in) and can grow over 2 m (6 ft 7 in) high.

[2] The funnel-shaped flowers are light to creamy yellow with brown central stripes on the outer petals.

[2] Echinocereus waldeisii is a steno-endemic species found in the semidesert brushlands of Mier and Noriega region, on the border of the Mexican states of Nuevo León, Tamaulipas, and San Luis Potosí growing between elevations of 1,200 to 1,500 m (3,900 to 4,900 ft).

[citation needed] The species is named in honor of Dieter Waldeis, who discovered it.