Cactées, 57. 1868.
Plants straggling, very tall and slender, sparingly branched at any level. Stems initially erect, later sprawling or clambering, long cylindric, 12–60 (–130) × 0.6–1 (–2) cm; ribs 8–10, crests low, uninterrupted or shallowly undulate; areoles 1–2–5 mm apart. Spines (9–) 11–13 (–17) per areole, stiff and straight, usually tan, brown, or black, sometimes yellow, pale-pink, ashy white, or gray, sometimes black central spines contrasting with white radial spines; radial spines 8–16 per areole, 2–5 mm; central spines 1 (–3) per areole, closely appressed (except at the stem tip), terete, 4–9 mm. Flowers 3.5–6 × 3.5–7 cm; flower tube 15–20 × 7–18 mm; flower tube hairs 3–5 (–10) mm; inner tepals rose-pink with darker-pink to magenta midstripes, proximally darker, 25–35 × 4–12 mm, tips relatively thin and delicate; anthers yellow; nectar chamber 1–4 mm. Fruits dark green to brownish, 2–3 cm, pulp white. 2n = 22.
Phenology: Flowering Mar–Apr; fruiting 2 1/2-3 months after flowering.
Habitat: Tamaulipan thorn scrub, alluvial soils
Elevation: 0-200[-1100] m
Tex., Mexico (Coahuila), Mexico (Nuevo León), Mexico (Tamaulipas)
Echinocereus poselgeri, with tuberous roots and erect, slender, elongate stems, superficially resembles some Peniocereus species. The polyphyletic genus Wilcoxia Britton & Rose formerly included this species along with species of Peniocereus. The flowers, fruits, and seeds of E. poselgeri are typical for Echinocereus, quite similar to those of E. reichenbachii.
"-5mm" is not declared as a valid unit of measurement for this property."thin" is not a number.