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Archive for December 30, 2009

Thursday, 31 December – South east of Petrolina

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.

Wednesday, 30 December – South west of Petrolina

Today’s outing was aimed at confirming the widespread distribution in this area of Discocactus bahiensis ssp bahiensis (D.b. for short). I recorded 9 separate stops, but they were all brief, just to confirm that D.b. was there, and in many locations they had different companion cacti, but on the whole, if we had spent more time at some of the stops, we would have found the companions there as well – may be.

D. bahiensis can be quite variable here and reminded me of seeing Gymnocalycium spegazzini in Argentina, that again can vary in strength of spination and colour of the epidermis. One such variants was given the name D. subviridigriseus, which is now a synonym under D. bahiensis.

We started at S1630 and S1631, which were quite bare, vegetation wise. D. bahiensis was there in quite some numbers, hiding among the dry grass. They tended to grow in clusters, so that if you took a photograph of one, you’d see another dozen without having to change your position, just the zoom range on the camera. As in most of the other locations, they seemed to happily share their habitats with goats and the odd cow.

As we drove a few km between stops, we’d see Cereus jamacaru. Yesterday we noticed that we were approaching a full moon phase and with sort sharp showers again building up, the night flowering cacti were getting ready to do their thing again tonight. 

S1632 gave us Melocactus zehntneri, Pilosocereus gounellei, P. pachycladus and Tacinga inamoena (in flower)

S1633, at 13:30 by now, and the storm clouds started gathering. The buds on the Discos were well advanced here and it looked like a flowering feast was due after 6 p.m. – when it would be dark.

S1634 and Tacinga palmadora, T. funalis, Pereskia bahiensis and Arrojadoa rhodantha had joined the list of cacti found here. T. funalis was a Marlon find and this was a mature plant with fruits. John Gander had invited me to speak at the Tephrocactus Study Group in May (Covering Opuntia s.l.) and I now have pictures of all the Tacinga species. Saw some being pollinated by hummingbirds as well, but in shady spots under the shrubs where cameras don’t reach.

S1635 was more Discos while at S1636 we found a lone Stephanocereus leucostele – peculiar how these occur in singles rather than in stands like so many of the other ceroids, and for Cereus albicaulis,  one of the less interesting cacti, at least visually.

S1637 was a special stop for Melocactus pachyacanthus, supposed have white seed pods – according to John – who thought that these plants with a very pale pink fruit, were more like M. zehntneri. Marlon explains that this is just variability within the species and that the spines, blue epidermis and fruit say ‘M. pachyacanthus’. We’re due to see ‘the true’ M. pachyacanthus in days to come and I promise to include pictures that may help the ID.

S1638 was the last stop of the day before trying (and failing) to outrun the storms that had been building up. We got back safely. Our hotel has a restaurant on the top (7th) floor, from where we observed the spectacle of different thunderstorms fighting it out along the Rio Sao Francisco. Cliff stayed up after the rest of us had gone to sleep and reports that some lightening bolts were practically overhead, making the hotel rock! Me? Fast asleep as usual.