A new species of cactus from the Valle de los Volcanes (Arequipa, Peru): Corryocactus volcanicus (Cactoideae, Cactaceae) Author Pauca-Tanco, G. Anthony 0000-0001-6367-5345 Universidad Católica San Pablo, Facultad de Ingeniería y Computación, Escuela de Ingeniería Ambiental. Quinta Vivanco S / N Urb. Campiña Paisajista, Arequipa 04001, Perú gpaucat@ucsp.edu.pe Author Hoxey, P. 0000-0003-4568-4568 Instituto Científico Michael Owen Dillon (IMOD). Av. Jorge Chávez 610, Arequipa 04001, Perú paul@hoxey.com text Phytotaxa 2025 2025-12-12 733 3 282 288 https://doi.org/10.11646/phytotaxa.733.3.2 journal article 10.11646/phytotaxa.733.3.2 8ee6f02c-dd3e-4099-8912-5866277e337a 1179-3163 18420473

TABLE 1. Comparison of characteristics between Corryocactus volcanicus and the related species C. brevistylus and C. brachypetalus.

	C. volcanicus	C. brevistylus	C. brachypetalus
Habit	Columnar, up to 3 m high, with basal branching.	Columnar, up to 5 m high, with basal branching.	Columnar, up to 4 m high, with basal branching.
Ribs	7–10	6–9	7–9
Areoles	Circular, 9–19 mm in diameter, spacing 22–30 mm.	Circular, 7–12 mm in diameter, spacing 20–40 mm.	Circular, up to 10–15 mm in diameter, spacing 20–40 mm.
Spines on branches (not basal stem)	14–17, up to 105 mm long.	Up to 15, 100 (–200) mm long.	Up to 20, up to 160 mm long.
Flowers	Pale yellow, almost white, 70–77 × 50– 53 mm, without a constriction between the hypanthium and the pericarpal.	Golden yellow, 80–110 × 70–100 mm, with a constriction between the hypanthium and the pericarpal.	Yellow, orange or reddish, 60 × 40–60 mm, without a constriction between the hypanthium and the pericarpal.
Fruits	Globular, 75 mm in diameter. Spines 27–33, up to 20 mm long, slender, soft and flexible.	Globular, 70–100 mm in diameter. Spines up to 40, 10–20 mm long, rigid and sharp.	Globular, 60–70 mm in diameter. Spines 10–12, up to 10 mm long, stiff and sharp.
Seeds	Blackish-brown, matt lustre, 1.76–1.90 x 0.65–0.79 × 1.26–1.33 mm.	Brownish, matt lustre, 2.08–2.25 × 0.70–0.96 × 1.32–1.51 mm.	Blackish, matt lustre, 1.53–1.79 × 0.64–0.75 × 1.13–1.34 mm.
Distribution	Endemic to Peru. Restricted to Valle de los Volcanes, Andagua, Arequipa. Elevation range 2700–3800 m.	Native to the western Andes of Peru and Chile. From latitudes S13.6° to S20.0°. Elevation range 2200–3900 m.	Endemic to Peru, in the coastal areas of Ica, Arequipa, Moquegua and Tacna. Elevation range 200–1200 m.