Acanthocereus horridus* Britton & Rose 1920
Plants shrubby, much branched, semierect, stout. Stems three-angled and winglike, dark green, to 10 cm (3.9 in) wide, with undulating margins.
Areoles large, 2.5–6 cm (1–2.4 in) apart.
Central spines 1-2, stout, brownish, becoming gray, to 5 cm (2 in) long.
Radial spines 1-6, short, conical, brown or black, becoming whitish, to 1.2 cm (0.5 in) long.
Flowers to 20 cm (7.9 in) long.
Fruits glossy light red, with large areoles bearing white wool, dehiscent, to 3.5 cm (1.4 in) long.
Distribution: southeastern Mexico, Guatemala, and El Salvador.
References: Anderson E.F. - The Cactus Family