Eulychnia vallenarensis P.C. Guerrero & Helmut Walter, 2019

Guerrero, Pablo C. & Walter, Helmut E., 2019, Nomenclatural novelties and a new species in Chilean Cactaceae, Phytotaxa 392 (1), pp. 89-92 : 89

Eulychnia vallenarensis P.C. Guerrero & Helmut Walter , sp. nov.

Type: — CHILE: Region of Atacama, 20 km south of Vallenar, Panamericana Road km 645, 28.71338°S, 70.76097°W, 741 m. a. s. l. Guerrero 1258 (holotype CONC 185660!).

Diagnosis: — Eulychnia vallenarensis is similar to E. acida from which differs by a shrubby habit (1–1.5 m vs. arborescent up to 6 m), semi-procumbent branches (vs. erect to ascending), shorter diameter (8–10 vs. 10–15 cm), with 8–10 ribs (vs. 9–16), and 1–5 radial spines per areole (vs. 1–10).

Description: —Plants shrubby, 1–1.5 m high, forming large mounds. Branches sub-procumbent, with superior portions pointing upwards, 8–10 cm in diameter, yellowish green. 8–10 low ribs, 2.5–3 cm wide. Areoles with short grey felt, ca. 1 cm in diameter, 2–2.5 cm apart. Spines acicular, not numerous, new ones blackish, soon turning grey; 0–5 radials, 1–5 cm, mostly on inferior part of areole; 1–3 central ones, 5–15 cm. Flowers subapical to lateral, 6–8 cm; tepaloids spathulate with tips, always white, sepaloids always green; axils of bract-scales with scant, short and grey wool. Fruits mucilageneous, 5–7 cm, orange when mature, covered as for the flower. Seeds numerous, ca. 1.5 mm long; testa tuberculate and more or less ribbed.

Etymology: —Species epithet refers to “Vallenar”, which is the main site around where the species occurs.

Distribution: —From north of Domeyko (29° S) to the Rio Huasco Valley (28.5° S) at strictly inland habitats between 600 and 1300 m.a.s.l.