3. Eriosyce choapensis (F.Ritter) P.C.Guerrero & Helmut Walter comb. nov.

Pyrrhocactus choapensis F. F.Ritter, Succulenta (NL)12: 133. 1960. Basionym.

≡ Pyrrhocactus choapensis F.Ritter in Succulenta (Netherlands) 1960: 133. 1960 syn. sec. Tropicos ≡ Horridocactus choapensis (F.Ritter) Backeb., Cactaceae 6: 3793. 1962 syn. sec. Tropicos ≡ Neoporteria choapensis (F.Ritter) Donald & G.D.Rowley in Cact. Succ. J. Gr. Brit. 28: 55. 1966 syn. sec. Tropicos ≡ Eriosyce curvispina var. choapensis (F.Ritter) Katt., Eriosyce (Cactac.) Gen. Revis. Ampl. 1: 117. 1994 syn. sec. Kew WCVP (2019).

Type.

Chile, Southern America, Coquimbo Region, Choapa, Illapel, May 1954, F. Ritter 238 (Holotype: ZSS 005073, Isotypes: SGO, ZSS) .

Iconography.

F. Ritter, Kakt. Sudam. 3, 1980.

Morphological notes.

Stems subglobose, dark green, often burnt brownish, 5-10 cm diameter Roots fascicular with a short thin taproot. Ribs 15-22, obtuse, deeply notched, 1.0-1.5 cm high. Areoles long-oval, 1cm, 1 cm apart. Spines are thin, acicular, grey-brown, short, 1-2 cm; radial ones 8-10, somewhat curved; central ones 4-9, somewhat thicker. Flowers funnel-form, 3.5-4.5 cm; pericarpel and hypanthium bract scales tiny, red, axils with white inconspicuous wool; nectary isodiametric; style pinkish, stigma lobes yellow; perianth segments narrow lanceolate, pale yellow with a faint purple mid-stripe. Fruits 1.5-2 cm, barrel-form, indumentum as for the flower; perianth remnant attachment area wide, basal pore large. Seeds small, 0.8-9 mm, round oval, blackish brown; testa cells arranged in ribs, medium-domed; hilum oval, positioned nearly basal, micropyle in a groove.

Distribution.

Endemic species occurring strictly inland, from Illapel (31°S, 71°W) to Tilama (32°S, 71°W) at elevations between 400 and 1200 m.

Conservation status.

The Extent of Occurrence (EOO) of E. choapensis is estimated at <5000 km2, with its populations severely fragmented due to landscape anthropization. There has been an estimated decrease in population size and the number of localities, as well as a loss of habitat quality due to mining activities, stump removal, and livestock. We propose to classify the species as Endangered (EN) according to criteria B1ab(i,iii,iv).