Original Description

H. Middleditch in Chileans, 11(37): 21 (1979 publ.1980)

Globular to somewhat elongated-globular, solitary or clumping with 5 to 8 (- 9) heads. Body up to 12cm in diameter, grey-green covered with grey-white coating. 

Ribs becoming 12 - 16, obtuse to acute, upright to slightly spiralling, with well-defined acute to obtuse groove between base of ribs. Top of ribs more or less rounded, barely divided into tubercles by slight depressions between areoles. 

Adjacent areoles usually touching but may be up to 15mm apart. Young areoles 6 - 8mm diameter, covered with soft orange-brown hairs which obscure the growing point, then becoming black and finally appearing to be almost bare. 

Outer spines 5 - 7, radiating, projecting markedly, curved backwards slightly, 10 - 12mm long, the lowest often the longest, together with an occasional one or two short, slender, almost bristle-like spines from the upper part of the areole; central spine one, straight, projecting outwards, 33 - 38mm long, round, tapering, some 1mm diam. at the base. All spines are chestnut brown in apex, rapidly becoming grey-black and then grey. 

Flowers and fruit not yet known. 

Type locality:

Coastal hills around Antofagasta, north Chile. Type plant: Rose 19410 in New York Botanical Garden Herbarium.”

The species occurs from Paposo and Blanco Encalada in the south to Cerro Moreno in the north. Large populations are found in the coastal hills near Morro Moreno and down to sea level at La Chimba. 

Comments

Harry Middleditch's description is based on  a plant collected by Rose in 1914 in the coastal hills around Antofagasta that previously had been identified as Echinocactus marginatus collected by Thomas Bridges. 

Holotype of Copiapoa atacamensis Middleditch J. N. Rose 19410 with Mrs. Joseph N. Rose, 31 Oct 1914 NY Specimen ID: 581212 Specimen Notes: Two specimens form this Holotype: flowers & a copy of the Fig. 99 from Britton & Rose, Cactaceae (NY 581212) and pieces of stem (NY 581213)
	J. N. Rose 19410 with Mrs. Joseph N. Rose, 31 Oct 1914 NY Specimen ID: 581213 Specimen Notes: Two specimens form this Holotype: flowers & a copy of the Fig. 99 from Britton & Rose, Cactaceae (NY 581212) and pieces of stem (NY 581213)

 

Initially, Ritter also used the name C. marginata for this plant, but in his Kakteen in Südamerika Band 3, he recognised that the true C. marginata grew south of Caldera. His decided to call the Antofagasta plants Copiapoa boliviana, based on Pfeiffer's 1847 rather vague description of Echinocactus bolivianus that was also based on a plant collected by Bridges. The area around Antofagasta was at the time Bolivian territory.  Pfeiffer had reduced Echinocactus bolivianus to synonymy under E. echinoides so that Copiapoa atacamensis may be the best choice as the valid name for this plant, even though is considered to be an incorrect name (ICBN Art 57.1) as it is based on an incorrect name (IOS Index of names of Cactaceae published 1950 - 1990 from Repertorium Plantarum Succulentarum, edited by Urs Eggli & Nigel Taylor).

Studies in the field reveal that clumps of plants with more than nine heads occur and that the flowers and fruits are typical of the genus.

In the south at Blanco Encalada, C. atacamensis occurs among rocks in the ravines of the coastal hills. 

There are superficial resemblances to C. calderana, which occurs much further south, north of Caldera, but C. calderana tends to be more columnar with age.

References in Literature

Distribution

PK Comments

We saw this taxon at Blanco Encalada and in the Quebrada Botija, as small, solitary plants near the valley floor.

Rudolf Schulz and Leo van der Hoeven awarded their 'best atacamensis' price to a population high in the hills above Botija. My attempts to look for these plants on Cerro Moreno were thwarted by a thick layer of clouds at around 50 m altitude. Climbing some 450 m. in thick fog just did not appeal. Rudolf Schulz reports that plants here are more plentiful than seen around Botija, but not as large and white waxed as at Botija.

Seen during our Copiapoathons at:

2001: S050, S067, S068
2003: S141
2004: S284

See also Copiapoa calderana