Selenicereus spinulosus

[1] Other sources claim that this species can be found in the states of Texas, Coahuila, Nuevo León and Tamaulipas.

[4] Plants were collected from the lower Rio Grande Valley of Texas in the United States, but this population may have been extirpated as it has not been seen outside of cultivation in some time.

[2] The specimen is commonly found growing on top of sun-exposed limestone outcrops as well as climbing on other plants in the sierra madre oriental hillsides and submontane matorral (scrub).

Stems scandent, clambering or sprawling, branching, producing aerial roots, stiff, to 1-2(-5) m long, 2–3 cm thick; ribs 4–6 or more, later terete, acute; areoles 1,5–2 mm on Ø, reddish brown at first, later greyish brown, internodes 1,5-2,5 cm; spines 6–8, 1 mm long, acicular, white or yellowish, later blackish, radial spines 5–6 central spines 1–2, basally 0,25 mm in Ø above the swollen bases, apically attenuate-conical, circular in cross section, the bulbous bases 0,5 mm in Ø, hairlike spines none; epidermis light green, somewhat shining.

Flowers produced from areoles near tip, 8–14 cm long, 7–8,5 cm in Ø, nocturnal but stays open for 2 2–3 days (John Ellis, UK), tepals rotate; pericarpel covered with spines, but no hairs, bracteoles small, triangular, reddish; receptacle ca 5 cm long, green, with clusters of 7–12 spines, 4–5 mm long, brownish, but no hairs; outer tepals 5,5–6 cm, narrowly oblong, acute, brownish; inner tepals 7,5 cm, 11 mm wide, narrowly oblong, acute, white, sometimes with pink base or pinkish throughout; stamens white, much shorter than inner tepals; style yellow, stigma lobes 9–11.