Discocactus hartmannii

(K. Schumann) Britton & Rose 1922

2008, Paraguay, San Pedro

Surveys

2008, Paraguay, San Pedro, Capiíbary, A&M 252 Show on map

01-9545

02-9541

03-9557

04-9548

05-9551

06-9564

07-9561

08-9563

09-9576

10-9575

11-9580

12-9581

13-9560

2011, Brazil, Mato Grosso do Sul, west of Caracol, A&M 719 Show on map

14-1120794

15-1120795

16-1120808

17-1120801

18-1120810

19-1120804

20-1120803

21-1120814

22-1120816

23-1120821

2011, Brazil, Mato Grosso do Sul, Caracol, A&M 720 Show on map

24-1120826

25-1120827

26-1120828

27-1120829

2011, Brazil, Mato Grosso do Sul, Caracol, A&M 726 Show on map

28-1120970

29-1120971

30-1120972

31-1120974

32-1120976

33-1120977

Synonyms

Echinocactus hartmannii*, Discocactus magnimammus ssp. bonitoensis, Discocactus hartmannii ssp giganteus, Discocactus magnimammus, Discocactus hartmannii ssp magnimammus, Discocactus heptacanthus ssp. magnimammus, Discocactus mamillosus, Discocactus pachytele, Discocactus patulifolius, Discocactus hartmannii ssp patulifolius, Discocactus hartmannii ssp setosiflorus, Discocactus silicicola
* Basionym

Distribution

Brazil (Goiás, Mato Grosso do Sul), Paraguay (Amambay, Caaguazú, San Pedro)

Conservation status

(4) Data Deficient, DD

Comments

Following some surveys conducted in October 2008 in Paraguay between Capiibary (Dpt. San Pedro) and Ygatimí / Reserva Natural del Bosque Mbaracayú (Dpt. Canendiyú) through Curuguaty (still Dpt. Canendiyú), we noticed that the campos cerrados / limpios of this area of the country, that represent part of the habitat of Discocactus hartmannii (K. Scumann) Britton & Rose (Esser 1982, 46, fig. 25; vegetation map out of the text), are disappearing because of their conversion into agricultural land, a danger that has already been filed by Metzing (1994). The area of the Reserva Natural del Bosque Mbaracayú, on the border with Brazil, is well protected and also includes some cerrados, but we could not detect the presence of D. hartmannii. The only useful survey of the taxon was done in Capiibary, near the homonymous river, in the territory of one estancia which is still not used as agricultural land. The population encountered consists of approximately fifteen pieces arranged on a piece of land of about 200 square meters, among the fields of another property. Although we do not have sufficient data relating to the conservation status of D. hartmannii throughout its geographic range, it seems appropriate to point out a possible risky situation that should be investigated with further research. For this reason we suggest an updated assessment of the conservation of the taxon from Least Concern, LC, (Hunt et al. 2006, Text: 326) to Data Deficient, DD. (October 2010)

Following what we had already investigated in Paraguay in 2008 for Discocactus hartmannii (K. Schumann) Britton & Rose (Anceschi & Magli 2010, 39) in August 2011, we conducted surveys in the Pantanal area, between the Depto Santa Cruz in Bolivia and the State of Mato Grosso do Sul in Brazil, on a group of taxa of the genus Discocactus Pfeiffer. In the far south west of Mato Grosso do Sul, in the area between Bela Vista, Caracol and Porto Murtinho, we found D. hartmannii, a taxon that we had already documented in the area of Capiibary, in the extreme southeast of the Depto. San Pedro (PY). As found in Paraguay, even here, for the ever-increasing land conversion into agricultural use, the populations have been fragmented into groups of few individuals, surviving only in bands of land left as dividers between one cultivated field and another. It is evident that this fragmentation and the reduction in the number of individuals cause local extinctions, with the consequent reduction of the genetic variability. Having surveyed, in 2008, only the Paraguayan habitat of the species, we have been cautious in assessing the degree of risk, passing from Least Concern, LC (Hunt et al., 2006, text: 326) to Data Deficient, DD (Anceschi & Magli 2010, 39). Experiencing later the serious Brazilian situation, and in accordance with a previous evaluation by Braun & Esteves which assigned Critically Endangered, CR (2001, 3: 60-61), to populations included in the current concept of D. hartmannii (D. hartmannii ssp. giganteus, D. magnimammus, D. magnimammus ssp. bonitoensis, D. mamillosus, D. patulifolius), we prefer to update our evaluation as: Critically Endangered, CR B2ab(ii,iii,iv,v). (June 2013)

Genus

Discocactus

Other species

boliviensis
ferricola
hartmannii
horstii
placentiformis