Eriosyce mutabilis (F.Ritter) P.C.Guerrero & Helmut Walter, comb. &, 2024

Walter, Helmut E., Cadiz-Veliz, Aron, Merino, Beatriz M., Villalobos-Barrantes, Heidy M. & Guerrero, Pablo C., 2024, Taxonomic dissection based on molecular evidence of the Eriosyce curvispina complex (Cactaceae): identifying nine endemic species from Central Chile, PhytoKeys 237, pp. 117-139 : 117

7. Eriosyce mutabilis (F.Ritter) P.C.Guerrero & Helmut Walter, comb. & stat. nov.

Pyrrhocactus horridus var. mutabilis F. Ritter, Kakt. Sudam. 3: 946. 1980. Basyionym.

≡ Eriosyce curvispina var. mutabilis (F.Ritter) Katt., Succ. Pl. Res. 1: 117. 1994.

Type.

Chile, Southern America , Coquimbo Region, coastal spur N of Los Vilos, December 1955, F. Ritter 223b (Holotype: U 0249320, digital image!). (Image available at https://bioportal.naturalis.nl/en/specimen/U__0249320) .

Iconography.

F. Ritter, Kakt. Sudam. 3, 1980; F. Kattermann, Succ. Pl. Res. 1, 1994.

Morphological notes.

Stems green, often burnt brownish, branching, 8-15 cm diameter Ribs ca. 16, 1.2 cm high, deeply notched. Areoles oval, 0.6-1.0 long. Spines brown, later grey, thickly acicular; radials 9-12, 1-3.5 cm, slightly bent; central ones 3-7, 1.5-4 cm long, shorter ones straight, longer ones bent upward. Flowers funnel-form, 3-4 cm; pericarpal and hypantium bract-scales small, axils with inconspicuous wool; perianth segments 1-1.2 cm broad with short tips, pale yellow or brownish yellowish, often with a pale reddish mid-stripe of various width; ovary isodiametric, style reddish, stigma-lobes yellow. Fruits barrel-shape, 1.5 cm, indumentum as for the flower; perianth remnant attachment area wide, basal pore large. Seeds 0.9-1.1 mm, round oval, opaque, brown; testa tuberculate and ribbed; hilum oval, position ventrally oblique, micropyle in a groove.

Distribution.

Endemic species, occurring between Los Vilos (31°S, 71°W) and Los Molles (32°S, 71°W), near the coast.

Conservation status.

the extent of occurrence (EOO) of E. mutabilis is estimated to be less than 100 km2, with its populations severely fragmented by population centers and road openings. Additionally, there has been a decrease in population size and the number of localities, as well as a loss of habitat quality due to real estate expansion, forest fires, and destemming. We propose to classify the species as Critically Endangered (CR) according to criteria B1ab(i,iii,iv).