So – it was our last day in Patagonia…  the region is defined by the Río Colorado that forms the border between the provinces of Neuquén and Mendoza, and last night we were almost there, we had made it (by midnight!) to the town of Chos Malal. Our target area was a high pass between two volcanos – Volcán Wayle and Volcán Tromen – we were looking for our last Benthamiella species – Benthamiella graminifolia (the one with leaves like grass!), that we had failed to find a few days earlier in the Estancia of Quichauré.

Volcán Tromen was spectacular – the lava flows were obvious and you could see the history of eruptions clearly. It is a perfect cone with a caldera, but looks like it has not been active for some time.

The flows of lava were a mixture of shiny basalt and a sort of bubbly cinder (I am sure there are correct terms for this!) – they were about 30 metres high!

We had been told that the plant was to be found where the lava flows were near to the road – so we began looking. I went down to the edge of the flow and walked all along for ages, then doubled back; Franco and Juan went the other way towards the lake, and Gloria crossed the road to the other side. Finally, Gloria looked in the rocky area right near where we had pulled off the road – and there it was! Looking very grassy indeed – so exciting to have found one of our “signature” plants on our last day.

Like all the other Benthamiella species we have found, Benthamiella graminifolia was past flowering, but still had lots of old dried flowers (the darker tan colored bits). The leaves are much longer than the other species we have seen

The whole cushion grows from a single root like a carrot – in texture as well as in shape

We also thought we had found Pantacantha ameghinoi again, but the plant, upon closer inspection, turned out to be a member of the verbena family – a Pantacantha mimic! The number of different life forms in these high elevation deserts is limited – cushions, spiny shrubs, herbs, grasses….

If you look carefully you can see the leaves of this plant are opposite, and the flowers have smaller calyces than the Pantacantha we collected in Primeros Pinos

So, collecting successfully completed, we had to begin the long journey back to Cordoba (more than 1000 kilometres) in the early afternoon. No field trip in the Andes, however, is complete without a road incident….. we decided to carry on down the dirt road to connect up with Ruta 40 (again!), but…. The road stopped and turned into a stream bed – the tractors were there fixing it, sort of – but as our truck was not 4WD there was no way through….

You can just see the truck, Gloria, Franco and Juan in the distance – it doesn’t look so bad in the photo, but trust me!

We were getting into the really tall Andes now – this is (we think!) Volcán de Domuyo, which at almost 5000 m elevation was completely snow-covered; the tallest peaks in the Andes are in central Argentina, Cerro Aconcagua, the tallest peak in the Andes at almost 7000 m, is near the town of Mendoza

Turning around and heading back the way we came, another road appeared – the satnav told us to take it and that it would connect up with Ruta 40 at a place called Buta Ranquil. So, after a certain amount of discussion, it was decided that it would save us time and cut two sides of a triangle. Not so. No one had been on it for ages, and about halfway down the back of Volcán Tromen Juan pointed out that if we had to turn around again there was no way we would make it back up the hill! So on we went, fixing the road as we went by throwing stones into ditches and shovelling away ridges.

As road incidents go this wasn’t a bad one – lucky we all were good at heaving rocks! We finally hit Ruta 40 at Buta Ranquil, filled up and were on our way. Ruta 40 was only paved for about 10 kilometres though, so it was back to dirt. We drove for several hours through the beautiful vegetation type called 'monte' – a high elevation (>1000 m) dry scrub on volcanic rock – there were fantastic gorges and rock formations and the light, as usual, was unreal.

As we got near the town of San Rafael, vineyards and fruit orchards began to appear – we were into the wine country. All of these orchards and vineyards are irrigated, there were some that had obviously failed and were totally dry. I wonder about the sustainability of an agriculture so dependent upon water from outside the region…. 

We finally got to San Luis, our destination (still 500 km from Córdoba), at midnight – fortunately in Argentina everything starts late and is still open at midnight, the schedule is a bit like Spain, no one even thinks of an evening meal until after 9 pm. Tomorrow it is another day of driving, and back to Córdoba for a bit of work organising everything in the herbarium and some work on Solanaceae for Flora of Argentina for Gloria and me.

And drive we did, through the miles and miles of soya, sorghum and maize – as we went north it got hotter and hotter (we are still in a heat wave here in Argentina!), and by the time we got to Córdoba it was 35 degrees (Centigrade!) and very humid. Unloading the truck at the Museum was like working in a steam bath. Now for the re-organisation of everything, and finishing off the plant drying. Franco drew the short straw and went to get the truck cleaned – it certainly needed it! Two weeks of Patagonian dust…..

I am sad to leave Patagonia, but will certainly be back! I need, badly need, the see all those Benthamiella species in full flower! Next stop on this trip though is Mendoza, where Nicotiana linearis and its friends await and I will see Iris Peralta, who worked with me at the Museum in 2001 on the tomato monograph…..

Franco and Juan have been working on the genomic structure of Solanum crispum – one of the species in the Dulcamaroid group that I have just finished revising (now in press in the journal PhytoKeys!). It mighty peculiar, and they were very keen to collect another accession to see if their observations were applicable to more than one collection.

Solanum crispum is a Chilean species, and like Solanum valdiviense, has only been collected a few times in Argentina and only in the Bariloche region. It has medicinal uses in Chile, and Cecilia thought that perhaps all the collections in Argentina were associated with Chilean settlers and that it was not really native here. We only had a few localities, but Cecilia had seen it just a few months ago just over the border in Chile – so we decided to go and see if we could find it. The border between Chile and Argentina is only about 40 km from where we were staying, so we left everything from the back of the truck in the hotel and set off.

Looking towards back to Argentina at Argentina’s customs sheds

Driving across the 17 km bit of 'no-man’s land' between immigration posts we realised why there had been so much fine dust all over the trails and roads in the area around La Angostura, where we had been staying. In June 2011 Volcán Puyehue that sits right on the Chile/Argentina erupted – the fine white dust was ash! I had completely forgotten about this eruption – the ash was several metres deep and at the top of the pass the Nothofagus trees were all dead – desolation. But some trees had a few live branches and new weeds were coming up along the road. I had never seen the results of a eruption so close to – the devastation is total.

Volcán Puyehue just covered with clouds – its slopes were white as if with snow

The ash was fine, whitish grey and several metres deep; it must have taken ages to clear this road after the eruption

In this part of Argentina it snows in the winter – this is a big skiing area – so there are a lot of road signs warning of slippery roads. I have never seen a warning of slipperiness due to snow and ash before!

The sign says “Caution – pavement slippery from ice and ash”

The forest on the Chilean side of the mountains is similar, but much wetter than that on the Argentine side, where the Andes act as a rain shadow. It was cloudy and misty and there were huge Gunnera plants along the streams. Gunnera is an amazing coloniser, it grows in many wet places in the New World tropics and has blue green algae (cyanobacteria) in its roots, providing it with extra nitrogen.

Gunnera magellanica (this southern species) is cultivated at Kew – you can see it all around the lake outside the Palm House!

Despite it being such a lush forest, we failed to find Solanum crispum – more Solanum validivense was all over the place, but not really what we were after. A frustrating start to the day – but it got worse!

Having spent half the day going to Chile, we decided to try to find one of the genera of Solanaceae found only in this area of South America – Combera. This little plant only grows high up in the mountains on scree slopes; it seemed the best and quickest way to get to a collecting locality was to go a ski area and take the chair lift up to where the plant was found.

So, arriving at the Chalpeco ski area we saw the telecabin going up and down, and went to buy tickets… what a disappointment! The lifts were not working and the woman firmly told us no one was allowed up beyond the top of the grassy slopes – Combera was up on the ridge. By this time it was 7pm and far too late to walk from the base up to the top – the total ultimate in frustration. This had to have been the worst collecting day ever – how can a mountain be CLOSED!

Combera grows on the ridge between Cerro Teta on the left and Cerro Escalera on the right – we could almost taste it up there!

After a great deal of discussion we headed north on Ruta 40 again – towards two more treasures, Jaborosa volkmannii and Pantacantha (another endemic genus). Let’s hope for better luck tomorrow!

Heading north into a rainstorm, the first rain we have seen since Puerto San Julian on the Atlantic coast!

So it turns out Rio Mayo is the national sheep-shearing capital of Argentina – who would have guessed! It was also one of the windiest places I have ever been – the hotel manager told us the rooms had no windows because they try to keep the weather out in the winter. Pretty grim. The street graffiti was great though..

I think this is actually advertising a brand of yerba mate, but it felt like Darwin was still following us

Today was a day for getting to the north, through the province of Chubut to the district of lakes in the province of Neuquén. It was a marathon drive – still along Ruta 40, which the GPS satnav had real trouble with, it has recently changed course and the poor machine kept getting confused. This of course necessitated a lot of discussion about which way to go – but we got here in the end. We had one last Benthamiella stop at an estancia where a plant had been collected in the 1940s – not much use, these estancias are huge and we had no idea even where to start. We had a go though, both in some hills and around a dry lake – no luck. The sun was unbelievably strong, if it hadn’t been so windy we would have fried.

The main houses of Estancia Quichaumes are the trees you can barely see in the middle distance – the only locality info on the label of Benthamiella graminifolia is “Estancia Quichaumes”; talk about needles in haystacks!

The area is super dry, at an earlier stop all the plants we were looking for were dried out and crumbly – despite it being completely dry, this lake was full of geese (cauquenes)

We decided to make tracks for San Carlos de Bariloche, a large town in the middle of the national park of Nahuel Huapi. The habitat again changed rapidly and quite abruptly – from dry steppe to mountains with forests of Nothofagus (southern beech), Austrocedrus (southern cedar) and Araucaria (monkey puzzle trees)! We stopped to see an old friend, Cecilia Ezcurra, who works in the herbarium in Bariloche, where we will go for an hour or so tomorrow. Then it is into the mountains where new plants await!

What a change from the dried out lake about 200 km to the south!

"I do not think I ever saw a spot, which appeared more secluded from the rest of the world, than this rocky crevice in the wide plain." - Charles Darwin (1838, Puerto Deseado, Patagonia, Argentina).

Rocky cliffs along the Rio Deseado

Charles Darwin landed in Puerto Deseado, where we woke up this morning, on 23 December 1838 – it must have looked quite different then! We usually associate Darwin’s ideas with his experiences in the Galapagos, but these Patagonian steppes had to have influenced his ideas – life is so difficult here, in the vastness of the steppes, living through incredible extremes of heat and cold. He rode and collected along the Río Deseado probably in the exact same area where we found Petunia patagonica yesterday. He probably even saw it!

Puerto Deseado

We actually didn’t follow in Darwin’s footsteps today, we just went looking for more plants! Along the road we saw a large group of choiques – Darwin’s rhea (the “avestruz” Darwin shot and ate before remembering to make a specimen!). In this species the males have harems of several females, all of whom lay eggs in the same nest. He then looks after the chicks (called charitos) – this was a male with about 10 little ones!

[choique]

Our first port of call was the Bosque Petrificado (Petrified Forest) National Park towards the west in the centre of Santa Cruz province. It is about 50 km off the main road on a dirt track and as we entered the landscape just got more and more spectacular. At the park headquarters where we needed to check in to show our permit and talk to the guardaparques (the national park system in Argentina is very organised, being a park ranger is a proper career and they are fantastically knowledgeable people) the ground is literally littered with the fossilised remains of upper middle Jurassic forests – huge trunks of long dead monkey puzzle trees more than 10 metres long abound; this was no crumbled fossil bed – it was amazing. The trunks are the remnants of Araucaria mirabilis – an extinct species belonging apparently to a clade now only found in Australia, thus providing rock solid evidence of the ancient connection of the southern continents. There was a really nice little museum as well, where there were great examples of some pretty amazing fossils that had been found there.

Bosque Petrificados - looking to the west, the large rocks in the front are fossilised tree trunks!

I haven’t yet properly introduced my colleagues…  all are from the InstitutoMultidisciplinario de Biología Vegetal of the Universidad Nacional de Córdoba – a real powerhouse of South American botany. I am lucky tohave such good colleagues for field work – although my Spanish  is pretty good, as a group we find more plants and have more fun!

From left to right - Gloria Barboza, Juan Urdampilleta and Franco Chiarini (note the Araucaria mirabilis!!)

Although we had gone in towards the park looking for a special Nicotiana (we didn’t find it, but we have more chances to come), we came away with a real prize – Fabiana nana, a plant we had been seeking for the last couple of days. It is a tiny spiky cushion plant and looks like something you might avoid if you had the chance – but there it was with beautiful white flowers. The whole thing is only about 10 centimetres high, and the flowers are tiny. There are no leaves, the green stems do the work of photosynthesis – this is a common strategy in dry desert areas, it reduces water loss from leaves. Tiny leaves do form on new shoots, but they don’t last long! My colleague Iris Peralta has a student who is studying these plants and she has had a very difficult time getting DNA out of them – they are full of resin. Coping with life in Patagonia can be difficult! Guanacos are everywhere – the grazing pressure must be very high.

The leafless stems and tiny flowers of Fabiana nana

We carried on looking for plants along the main road, heading for some specific places and all the time looking for characteristic domed shapes of Fabiana or Bethamiella. The roadsides in Argentina all have shrines to Gauchito Gil – a gaucho from Corrientes who defied the boss and eloped with his daughter, and was a sort of latter-day Argentine Robin Hood who robbed from the rich and gave to the poor. The Gauchito is a driver’s “saint” and shrines vary from huge and elaborate to quite simple and personal. This one was kilometres from any village or habitation and quite new, older shrines have many little red huts and lots of flags. It is traditional to leave gifts of alcohol, cigarettes and red bunting.

At the last stop –again at 9:30pm – failing to find the target plant – we encountered another population of Petunia patagonica, it is becoming commoner now we are further south, but it seems we don’t find it unless it is almost dark! Still no seeds though, this will help tell us if this is a different genus to Fabiana. As we entered the tiny port town of San Julian it began to rain – it looks like the heat wave is over and we are really in for a big change.

This was the day when the plants were to begin – again though we began by driving a very long way! Our destination was the Pampa del Castillo where three species of the Solanaceae genus Benthamiella had been collected - old collections, but these plants are very rare and we are trying to hit every locality in the hopes of finding at least some of them. Benthamiella is a genus that is endemic to Patagonia, with 12 species in Argentina and Chile. These are tiny cushion plants of the steppes, hard to find!

As we drove south the landscape became more and more desert-like, the plants lower and lower and drier and drier. We began to see guanacos along the road, grazing in the weeds, and also in the native vegetation. These camelids are the wild ancestors of the “cultivated” llamas and alpacas of the Andes and are absolutely beautiful – they look like proper wild animals, sleek and beautifully colored.  Petrol stations are few and far between in Patagonia, so every time one appears everyone tries to fill up, there are always queues!

Petrol queues in the middle of nowhere!

We turned off for Pampa del Castillo, and began to search the steppe for Benthamiella. We found lots of interesting things, and it was very hot!, but no luck. The sight of four botanists, heads down looking at the ground must have looked absolutely crazy! The only creatures that would have seen us were rheas though – the area was absolutely deserted.

You can just make out Juan, Franco and Gloria heads down searching the steppes for Benthamiella!!

Rheas - the epitome of avian elegance, and not the slightest bit interested in us....

We drove and collected and drove – all the way to what was on maps as the town of Holdich – abandoned long ago. It must have been so difficult living in this dry exposed area – today it is a large oilfield, full of “grasshoppers” extracting black gold…..

This abandoned house had a deep basement and was full of beautiful old tiles - it must have been quite some residence at one time.

In a last attempt, we stopped at the last locality – not hoping for much – but success at last! Two species of Benthamiella! The flowers were less than 4 mm long, and dried up and almost falling off – we wondered if we had just walked by these plants earlier. Once you get your eye in for a plant, it appears everywhere – let’s see if we can find Benthamiella more efficiently tomorrow!!

Gloria with our first Benthamiella find.