Today we headed off to the south-west of Petrolina / Juazeiro (this is a twin city of half a million inhabitants in total, Petrolina is north of the Rio Sao Francisco, in the State of Pernambuco, while Juazeiro on the south shore is in Bahia). Marlon wanted to do some exploring along the BR 235, a dirt road, despite its grand route number.
Along this road were a number of localities for Discocactus bahiensis ssp. bahiensis, but recently, a Czech / German party had described a new taxon here, D. petrhalfari, named in honour of one of the members in the party. We tend to be rather sceptical about such new discoveries, because all too often they turn out to be nothing more than a minor variant or form of a previously described cactus. We made a number of stops in unlikely looking places only to be pleasantly surprised that the Discos were here, despite the heavy agricultural development.
Lack of time does not allow me to report the full stop list (S1639 to S1646) but in the main, they were short stops to confirm what did grow here and what did not. Most of the usual northern Bahia cacti were also spotted. I’ll single out S1643, where D. bahiensis ssp bahiensis (s.n. D. subviridigriseus) was found growing under cleared shrubbery and in grass as well as below the barbed wire fencing. These were huge plants and many were in bud promising a flush of flowers tonight. One plant with advanced buds was taken to become a herbarium specimen and thanked us for its impending doom by producing six flowers that were photographed back in the hotel.
The second stop I’ll single out is S1645, where we did indeed find a Discocactus, D. petrhalfari, that appears to be intermediate in most respects between D. zehntneri and D. bahiensis. Marlon will do some more studies on these plants and when time permits will hopefully treat us to an article with his findings. In the mean time, enjoy some of today’s pictures to see out 2009.
The Cactus Trip Diaries 
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