We left Huamachuco – joined by Emilio Perales, a friend of Tiina’s from the Agrarian University in Lima – so we were packed into the truck like sardines – something that got us rather hysterical towards the end of this long long day.

The area around Huamachuco, and this part of northern Peru in general, is home to a huge number of mines – mostly mining for gold, and sometimes copper as well. The method involves basically taking down the mountain bit by bit, mixing the earth with mercury and then evaporating off the mercury to extract the gold. This is definitely not gold mining Klondike style where nuggets are found – it involves big machinery!

These mines are all pretty high up, often in the puna, or Andean grassland

We intended to go to our next destination, the town of Mollepata, via a road that crossed the puna and went into valleys that are big collecting gaps. So up into the puna we went – the pass we crossed and then began to descend was called Altos de la Flor – and it was spectacular.

This area of puna was full of huge rocks, under which grew really interesting vegetation – but only where it could not be grazed by animals

Under one of these rocks we found what for me was the plant of the day – Saracha quitensis. One often sees the more common Saracha punctata, but this one was new for all of us. Solanaceae are fantastic plants – they come in all shapes and sizes, this flower looks nothing like a Solanum!

Saracha quitensis differs from the only other species in the genus, Saracha punctata, in its spines and narrower flowers

Climbing up some of the rocks we also found a species of the pineapple family (Bromeliaceae) genus Puya flowering high on the cliffs. The flower spikes of Puya can be very large indeed – last year in southern Peru we saw Puya raimondii, whose spikes reach several metres.

We don’t know what species of Puya this one is – but the close ups of the blue-green flowers will help with its identification (we don’t have permits to collect any plants other than Solanaceae, so we collected with photos only)

We tried one road down, and then another – no way down at all. Wither the roads stopped dead at tiny houses, or were so bad that no vehicles could pass. So we moved to plan B - well, really by that time it was plan D or E, but we had to go back to the main road and go another way. As we left the puna, an alpaca superciliously looked us in the eyes as if to say “Well, what do you expect, this is my territory!”

These high elevation grasslands are grazed by herds of llamas, alpacas and sheep – often seriously overgrazed

So on the road we went – one great aspect of travelling by road in Peru are the lorries. Each has a distinct painting on the back – we followed this one for a while, until he let us pass. The sign on the back says 'Imagine your destination, we will take you there' - quite a claim!!

The road to Mollepata passed through several Andean valleys – this means going up and down several hundred to a thousand metres in elevation each time, and twisting and turning on switchbacks. So a distance that might look like 20 kilometres on a map can be 50 or more! But all this up and down means going through lots of habitats were different plants grow – near a town called Santiago de Chuco we hit a real Solanaceae gold mine.

We think this is the species Browallia dilloniana – it had extraordinary black hairs tipped with orange glands

The wild tomato Solanum habrochaites literally covered hillsides in the valley just below Santiago de Chuco at elevations between 2500 and 3000 metres

We collected like mad, and then drove for Mollepata on a terrible road – and drove, and drove. We arrived after dark, always a tricky thing in Peru, but found a hotel of sorts. No one was available to cook food and there were no restaurants – so a crisis loomed. Fortunately for us, the lovely store owner who also managed the hotel organised someone to cook us a few eggs with bread, so things started to look a bit better.

The town of Mollepata was celebrating Mother’s Day a bit early though, and the party started at 9pm at the school just opposite the hotel; it went on until 4am – complete with loud music, dancing and general mayhem. It did sound like everyone was having a good time though!

Field work began in earnest today – we headed from the coast up into the mountains, the destination was Cajamarca, by fast road 6 hours away – but we were taking the road less travelled. We took a tiny dirt track up a dry valley to a village called San Benito; our research in the herbarium in Trujillo told us this would be a good place to look for some special endemics. Wild tomatoes are most diverse in the dry western regions of Peru – so I was hoping to see some of the species I have not yet seen in the wild.

It took us a while to find the right road – road signs don’t really seem important in Peru, people generally know where they are going I guess! The area was fantastically dry, with rocky slopes and tall columnar cacti. This is the northern part of the Atacama, the desert created by a combination of the cold ocean current called the Humboldt Current coming from Antarctica and the rain shadow of the Andes to the east.

The tall cactus peeking out from behind the hill is called Neoraimondia; Antonio Raimondi was a famous Peruvian botanist of the late 19th century and really began the exploration of the plant diversity of the country

The first plant we saw (well, the first one we were going to collect!) was a genus I have never seen in the field before – Exodeconus. It is an Atacama endemic, and this species is the only one to grow in northern Peru. Tiina collected a couple of other species last year in the southern part of the Peruvian coast.

The plants we saw in this valley were tremendously variable in size, from tiny with only a couple of leaves to large and fleshy and extending to a metre or more. It all depends on water, as is usual in a desert. Desert plants are masters at making do.

Exodeconus maritimus growing in a shady  place under a rock – some leaves on other plants were the size of saucers! The flowers are beautiful, bright white with a deep purple centre

The tomatoes soon began to appear, like Exodeconus growing in slightly wetter microhabitats. The first species we saw was Solanum pennellii – the closest relative of the tomatoes proper. It doesn’t have the pointed anther cone of the rest of the group, so was placed in the genus Solanum, rather than Lycopersicon, as the tomatoes used to be known.

We now recognise all of the wild and cultivated tomatoes as members of the genus Solanum, based on the molecular studies done by my colleague David Spooner in the early 1990s. His results showed tomatoes are closely related to potatoes; many characteristics of the plant form also support this evolutionary relationship. So we now group the tomatoes as part of the large genus Solanum, reflecting their ancestry and evolution more accurately.

Solanum pennellii has stubby anthers – here being buzzed by a small bee

All Solanum species are buzz pollinated by bees – the anthers open by tiny pores at the tips and female bees grasp them and set up a resonance inside using their flight muscles, pollen squirts out lands on the bee and she carries it to another flower – if you sit by flowering tomatoes long enough anywhere, bees will come and buzz, the sound is quite audible!

Tomatoes proper have a long beak on their anther cone, but there are pores inside – the beak is a shared evolutionarily derived character that tells all tomatoes are closely related to one another.

Solanum arcanum – a northern Peru endemic species only recently described by my colleague Iris Peralta (with whom I was recently collecting in Argentina), has the elongate beak typical of wild tomato relatives. This species began to appear a bit further up the valley towards the mountains

The small fruits of wild tomatoes are usually green and hairy, but even from them you can tell the species apart. The sepals of Solanum pimpinellifolium – the progenitor of our cultivated tomato – are strongly turned back, while those of Solanum arcanum (below) are always held flat – easy!

Solanum pimpinellifolium

Solanum arcanum

We were elated with our success at finding the wild tomatoes, all in flower, but were becoming disappointed about one special species we were seeking – Solanum talarense, an endemic to the dry coastal valleys of northern Peru and rarely collected.

We had almost given up, the road was going up the valley into wetter habitats and higher elevations, but then we saw it – possibly the rattiest plant I have ever seen! Eaten by goats, despite its ferocious prickliness, there it was hanging on in rocks by the roadside.

Solanum talarense amongst the rocks, completely eaten by goats (we think, but it certainly had been munched by something!)

Jumping out of the truck I felt prickles in my shoes – only to discover that several 2 cm long thorns had gone right the way through the bottom of my boots; it will be interesting to see how this affects them when we get to wetter places! Solanum talarense was most definitely THE plant of the day, totally weird and wonderful – a plant only a Solanum taxonomist could love.

The 'spines' on the stems and leaves of Solanum talarense are technically prickles, outgrowths of the surface – true spines, like those that went through my boot, are bits of stem. Prickliness does not seem to have deterred the animals eating this plant at all!

Ascents from the coast to the Andes in Peru are amazing – in a single day you can go from sea level and a dry desert to 4000 metres elevation and dripping wet cloud forest. This time we went over a pass that was only 3500 metres elevation, to descend again into the dryer valley of Cajamarca (via a couple of other passes – the geography is incredibly complex in northern Peru).

Wet cloud forest beckons ahead in the mountains

In the village of San Benito, in the cloud forest – in the pouring rain – we found our last wild tomato of the day. Solanum habrochaites used to be called Lycopersicon hirsutum, but when the time came to change its name to put it into Solanum, there already was a Solanum hirsutum (a European species) – so we had to think of another species name for it. The name we chose – habrochaites – means softly hairy in Greek; we thought it described the plant exactly.

The fruits of Solanum habrochaites are covered with long hairs each of which has a small sticky gland on top. These glands exude a substance that gives each wild tomato species its particular smell, and gives us that lovely smell of ripe tomatoes fresh from the vine

We reached Cajamarca at about 11 pm, a bit later than planned – maybe we spent too much time collecting in the desert, but none of us thought so! This first day collecting was a great success – lots of other wonderful northern Peru endemics and some real surprises and firsts for me (Leptoglossis schwenckioides, Browallia acutiloba and on and on).

Now for a day in the herbarium of the University of Cajamarca and a visit to the wonderful Peruvian botanist Isidoro Sánchez Vega, for whom I named a lovely species of Solanum a couple of years ago. I am hoping we find Solanum sanchez-vegae on this trip – maybe when we leave Cajamarca for points south. Can’t wait.

Posted on behalf of Sandy Knapp, Museum botanist on field work in Peru.

After a last push in the herbarium and a bit of shopping for containers for Erica to rear flies in (obtained by Maria in the Mercado Central in Lima, where you can quite literally buy anything!), we were ready to go…

Maria Baden and Tiina Sarkinen with the fruits of an amazing shopping expedition to the Lima Central Market – the plastic containers will be used to rear fly larvae we find in fruits of Solanaceae

Leaving Lima at 6am (to beat the traffic) we drove through grey, gloomy fog – typical weather on the coast at this time of the year. The fogs come in off the cold Humboldt current – making it cold and damp, but never truly wet; the unique vegetation of the coast lives entirely off the moisture from these seasonal fogs. Several endemic species of Solanum live in the lomas – or fog forests – but we are a bit too early to catch them. The foggy season has only just started and plants are only just beginning to grow.

The coast of Peru always fascinates me – it is such a dry desert, yet people live wherever water presents itself. At intervals between desert sections, the Panamerican Highway on which we drove north crosses small rivers coming from the Andes to the east, and there agriculture flourishes.

Sugar cane is a common sight in the river valleys; increasingly it is being grown under irrigation farther into the desert – surely an unsustainable practice. This is, after all, one of the driest deserts in the world!

Once we got further north, the skies cleared, the fog burned off and the sun came out – and on we went! When the Pacific came in view we all got out to have a look, even though the area was completely devoid of plants. The water is clear, blue and cold – we saw fishermen in tiny rowboats fishing what looked dangerously close to rocks just off the coast. This part of the coast is famous for its anchovy fishery – the fish are used for fishmeal, but also end up on pizzas worldwide.

Our rental pickup parked near the coast – it really is a desert!

Maria shooting video footage of the fishermen – the sea was an unreal colour of blue

One peculiar vegetation formation that occurs on the desert hills is the 'tillandsial' – patches of small bromeliads, plants related to Spanish moss or airplants, that are the only living things growing. Like all the other native plants of this coast, they get their water entirely from the fogs that come in off the sea. Their leaves are covered with scales that help trap the water from the air. In a way, they are like epiphytes, but on the ground!

Tillandsial near the town of Casma – this species is probably Tillandsia purpurea

We didn’t stop for lunch until quite late – between towns in river valleys there is nothing at all. When we did stop we had our usual coffee rating - coffee can be wonderful (10) here, or dire (0)– this rated about a 2, pretty awful, but the Inca Kola sugar canister made up for it. Inca Kola is the local soda pop – fluorescent yellow and sticky, it is said to be flavoured with lemon grass; I don’t believe it!

Tiina with the Inca Kola canister (we had to stop her asking to buy it, it is her favourite sort of enamel kitchenware!)

We made it to Trujillo and a wonderful colonial hotel; tomorrow we hit the herbarium on the search for more localities for Peruvian endemic Solanaceae. So – I’m sure we will find them, but the big question is – what will the coffee tomorrow morning be like?

I finished most of what I wanted to do (this trip!) in the Duke herbarium – so my kind hosts thought it might be nice to go see the rare and endangered (in the wild) Venus-flytrap in the swamp. I jumped at the chance – these extraordinary plants are common in cultivation, but the chance to see them in their native habitat was so exciting!

We were headed to the Green Swamp – near the coast of North Carolina – in the middle of the very narrow range of these wonderful plants. They only occur in the swamps of North and South Carolina in a radius of about 90 miles! We met an ex-graduate student of Kathleen’s and now professor at University of North Carolina Wilmington, Eric Shuettpelz and his student Alex Davila, who know this area well.

Carnivore country

The vegetation in these coastal areas is quite special – the soil is bright white sand and the forest are composed of various species of pines, interspersed with grassy open areas and shrubby thickets, called pocosins. The pine species are different in the pocosins and forests – it is an interesting mosaic.

The mosaic is maintained by burning – these areas are burned regularly through lightening fires and the Nature Conservancy, who look after these pieces of pristine habitat, regularly conduct controlled burns, usually in winter, to keep the shrubs from taking over. The main pine species of the open areas is the long-leaf pine – Pinus palustris.

Controlled burns are not so hot as to completely decimate the forest, but clear out the understory and let light in – this area was probably burned a couple of years ago.

The young plants of long-leaf pine persist in a grass-like state for years, until a fire comes along and opens the canopy so they can grow tall.

We emerged from our first pocosin – thick with holly, magnolias and lots of rhododendron and blueberry relatives – and looked down on the wet ground amongst the grasses, and there they were – the carnivores! Venus flytraps and sundews, growing together on the wet ground. Not quite the size of those of the film Little Shop of Horrors, but pretty exciting all the same. If you weren’t looking carefully, you would walk right by or even on top of them.

Venus flytraps (Dionaea muscipila) and sundews (Drosera leucantha) catch their prey in totally different ways – both with modified leaves.

Sundews have sticky glands all over the leaves that trap insects in their glue, then the stalks of the glands themselves bend to further engulf the prey.

Venus flytrap leaves are modified into a sort of snap-jaw trap – tiny hairs in the open surface trigger the folding of the leaf like a prison when an insect blunders in; the spiky leaf edges mean the trap is shut even before the leaf itself completely closes.

Insectivorous plants usually grow in nutrient-poor soils; it is thought that they obtain nitrogen much needed for growth from their insect prey. Charles Darwin was fascinated by insectivorous plants, and a good review of their biology and diversity was published in his celebration year in 2009.

The shut trap in this individual just has a piece of stick, so I think insect catching must be relatively rare!

Further on, in the grass under the long-leaf pines – we saw yet another famous carnivorous plant – the yellow pitcher plant Sarrecenia lutea. The insect trapping leaves of these plants are long erect tubes in which water collects – the rim is slippery and an unaware insect can plunge to its death, to be decomposed and its nutrients absorbed by the plant. Not quite as active as the flytrap, but pretty effective nonetheless.

The flowers of pitcher plants are large and showy and have a most peculiar umbrella-like style that looks like a flying saucer in the middle of the bloom.

This fly looks like it will probably escape – so again, trapping is not a common occurrence, the pitchers are not full of insects.

At the Green Swamp we also saw two other carnivorous plants – the butterwort (Pinguicula) and the bladderwort (Utricularia), and a host of other fascinating plants special to these swampy, nutrient-poor habitats. Members of the blueberry and rhododendron family – Ericaceae – are very common and important members of the shrub layer in these communities.

This blueberry relative – Lyonia lucida – has dry capsular fruits rather than the juicy berries we associate with its relatives.

We finished the day with another stop at Boiling Springs Lake – a more upland forest with pines and oaks.

The turkey oak-pine forest is more open than that we saw at Green Swamp.

At Boiling Springs Lake we saw bladderworts in abundance – tiny yellow flowers about 2 mm across emerging from the white sand at stream edges. The leaves of these plants trap water shrimp (Daphnia) and other minute water creatures – they open and shut using changes in water pressure and their movement has been shown to be among the fastest movements in nature. Quite amazing for something so tiny and seemingly insignificant!

The leaves of Utricularia are small globular 'bladders' – hence the common name – that trap microscopic organisms living in the water between soil particles in this waterlogged soil.

Leaving the forest, we were reminded of some friends not to take home with us! Ticks are common in these forests and we did find a few – big and little.

Thanks to the Green Swamp expedition team! Eric Shuettpelz, Alex Davila, Fay-Wei Li, Tiff Shao (hiding!), Layne Huiet and Jose Eduardo Meireles (Dudu)

Tiina Sarkinen, who until late March was working with me on South American Solanum, has now set out on her own with a new job at the Royal Botanic Garden, Edinburgh. We will continue to work together - the world of nightshade research is ever-expanding!

She left for our second big Peru trip at the beginning of April, and has just posted her first blog post through Edinburgh's website. The work is funded by National Geographic, so blogs will appear there too. Watch NaturePlus to see the work expand!

I go out to join Tiina on the 1st of May, after a brief stop-over to give a couple of lectures about Alfred Russel Wallace in the Amazon in the USA - our objective is the Cordillera of Huascaran and more exciting solanums!

When we arrived in Las Leñas late at night it had been raining and there was no mobile signal – in the morning it was restored and we received several worried calls from Mendoza, there had been landslides in the mountains on the road to Chile and since we hadn’t been heard from people were concerned! We had been blithely unaware, but decided to watch the weather as we collected.

From Las Leñas we were headed for the Valle Hermosa – beautiful valley – a place right near the border with Chile. This area is where the plane crash about which the movie “Alive” was made – the survivors were not far from civilisation in Argentina, but thought they were closer to Chile and walked for days in the high Andes. The mountains are beautiful, but dangerous. We left our things in the hotel, and told them we would be back at noon or so to collect them and carry on back to Mendoza….

The high Andes in central Argentina are very dry, above about 2500 metres elevation there is little or no vegetation; in winter these slopes will be completely snow-covered

As we drove up the valley, it was apparent that the rains had fallen and the vegetation was greener than I had seen for a long time. Patagonia had been so dry, but here it was almost lush, as dry deserts go. Crossing a small stream on the road, we found the first excitement of the day – Schizanthus grahamii – a plant I knew well from gardens but had never seen in the wild before. It was all over the banks of the stream, and individual plants varied a lot in flower colour, from pale to very deep pink.

The flowers of Schizanthus (sometimes called butterfly flower or poor-man’s orchid) are highly asymmetrical, with one large upper petal usually a different colour than the rest; in this species the upper petal is orange and the side petals pink

The pass into Valle Hermosa is at about 2700 metres elevation, and the view is spectacular. The valley is glacial in origin, and has been further sculpted by the rivers that run through it. We got someone to take our photo at the top with the valley behind! This valley is famous for its fly fishing, people come from all over to fish in the rivers; our photo was taken by the guide who was taking a presenter from a Brazilian fishing TV channel around the region.

The Mendoza team, from left to right Iris Peralta, me, Gualberto Salazar and Pablo Molina – Gualberto and I are leaning apart to show the lake!

Fishing streams in Valle Hermosa

The bottom of the valley is flat and rocky, again with the sand beneath, a perfect habitat for the Portulacaceae Iris was searching. She had collected there before, so this trip was really not to find new things for her, but for her to show Pablo how to collect and recognise these tiny little plants. And they were tiny and hard to find!

This is an annual species of Montiopsis that was growing in places where water had been standing but now dried out, on very loose sandy soil. The flowers were less than a millimetre in diameter – minute!

The flowers of these purslanes only open at midday – once they are open they are pretty easy to see, this species Montiopsis gilliesii (named for Gillies the Scottish botanist!) has bright pink flowers that are held flat against the ground, when the fruits begin the develop the stem stands erect and they are held up high. Who says plants don’t behave!!

We stopped to have lunch at the lake overlooked by Cerro Torrecillos (little towers, what a good name!), but they wanted to charge us 10 pesos to sit there, so on we went. By this time the skies were getting dark and we began to hear thunder from the mountains to the west.

Bearing in mind that there had been landslides we decided to return ….... first stopping at the pass to collect the purslanes that were now in full flower. The clouds billowed, and the thunder rolled – there was definitely a storm on the way! The extraordinary thing was that people in city cars were attempting the descent into the valley – let’s hope they didn’t end up stuck there! The road was definitely not for city cars……

Iris, Gualberto and Pablo racing around on the pass collecting as the storm rolled in

We got back to where we had left our things at 5 pm (a bit later than the noon we predicted!!) gathered all together and headed down the valley. We stopped at the Pozo de Animas, where we found another mixed population of tobaccos, this time Nicotiana linearis and Nicotiana corymbosa; the latter species we had also seen high up in the mountains – it has a huge distributional range and grows in many different vegetation types.

The Pozo de Animas (Well of Souls) is a natural feature of this karstic landscape formed by the collapse of rock above an underground cave created by water eating away the limestone. The hole is perfectly circular and the water is VERY deep

We arrived back in Mendoza at 11:30 pm, and discovered why everyone was a bit worried about us up in the mountains! The landslides near Uspallata, where we had been a few days before, were huge and had blocked the road to Chile in at least six places. One slide was almost a kilometre across and several metres deep – the clean-up was predicted to take days…..  fortunately no one was hurt, but hundreds of people were trapped. We had been lucky to go up the road in full sun and to see the mountains in all their glory before these unusual rains set in!

The flight to Mendoza was short and sweet, and I was met by my colleague Iris Peralta, with whom I had written a monograph of the tomatoes and their wild relatives when she was in London on a post-doctoral fellowship in 2001. We spent the afternoon in the herbarium, looking at the Solanum and Nicotiana from Mendoza province to see where was best to go in the field over the next few days.

Our first field excursion was to the valley of Cerro Aconcagua. Pablo Molina, a new PhD student studying the phylogeny of cacti and their close relatives the purslanes (Portulacaceae) came with us to look for his plants as well! The peak of Aconcagua is at almost 7000 m above sea level, making it the tallest peak in South America. The area around Mendoza and into the high mountains is a high elevation desert – the vegetation is of shrubs and grasses, and at higher elevations vegetation is almost absent.

The vegetation on the way up the valley to Uspallata is dominated by creosote bush (Larraea); this genus also occurs in the deserts of California and Arizona in the USA

All along the roadsides in the disturbed soil we found Nicotiana noctiflora – we were early enough in the morning to see the flowers still open; at one site a nectar-robbing carpenter bee was carefully alighting on each flower and biting a hole in the base to suck out the nectar – this species flowers at night (hence the name!) and is pollinated by moths

Although the area is arid and dry, in winter it is snowy and the pass over the mountains to Chile (this is a major connection between the two countries) is often closed; all up and down the upper parts of the valley were ski areas, very popular in winter. The region has been shaped by the action of glaciers and landslides – ancient rockfalls and terraces were easy to see with the light vegetation cover.

We came to Puente del Inca – now I truly felt I was following Darwin around! After the Beagle had rounded the tip of South America, the ship suffered damage that had to be repaired. They docked in Valparaiso, Chile to repair the damage. Darwin took two men with him and rode over the Andes and then to Mendoza, riding back across the Andes into Chile along exactly the same valleys we were driving along. He described the unusual geological formation of the Puente del Inca beautifully in his book about the voyage of the Beagle.

The stone bridge over the river was formed from the concretion of chemicals from a thermal spring – this was the site of a thermal spa in the early 20^th century with a posh hotel and baths. An avalanche completely destroyed the hotel (to the far right in the picture) but spared the church

Our first sight of Cerro Aconcagua came at Quebrada Horcones – it was a completely cloudless day – we were very lucky, the peak is often shrouded in clouds. What a mountain. Climbing it is tightly controlled – every year climbers die and they are buried in the “Cemeterio del Andinista” in the valley.

Quebrada Horcones is one of only a few places where climbers begin the ascent – apparently the record climbing time is 15 hours, incredibly speedy, most take longer and spend the night on the glaciers

Although we a lot of locality information for the Solanum and Nicotiana we were seeking, they were nowhere to be found. Like Patagonia, it was very dry, so we suspect it has been a bad year. We did find several of the purslane species Pablo and Iris were seeking though, on the way up an incredible set of switchbacks (called caracoles – snails – in Argentina) to a pass at 4000 metres.

Montiopsis andicola was named by John Gillies, a Scottish botanist who, between 1823 and 1828, explored this region botanically for the first time; this entire plant is smaller than a 5 pence coin!

The switchbacks to the statue of the “Cristo Redentor” were amazing – but the road had been fixed so it was full of cars and microbuses, the tourists in summer clothes had a shock at the top in the cold wind

Our amazing day ended with a new route back to Mendoza, along the way we collected some Fabiana for Iris’s PhD student at an amazing petroglyph site.

It had rained as we came down the valley from the high mountains and the resinous foliage of this species had a wonderful incense-y smell

Our last stop was at the plaque Iris and colleagues had organised to commemorate Darwin’s travels in the area. The plaque sits in the site of a petrified forest that Darwin described…  it was quite moving to think of him on horseback seeing these same hills and the same vegetation. Seeing it myself brought it home to me how much his entire experience in South America must have shaped his ideas, not just the Galapagos.

Just behind the plaque we think we found the Solanum I was looking for, but only as tiny plants just breaking the soil…..  frustrating, but I hope we find it elsewhere in the region, it seems to be common, but might just be fussy and not grow some years. What a day…. and at the very end, the mountain let us see it again from the top of the pre-cordillera, an ancient range just to the east of the Andes themselves, we were indeed very lucky!

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…..