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Mike Partridge

This article is again drawn from the Willy Smith cactus tour to Argentina and Chile which I enjoyed in November 2008 and will this time will cover the species of Tunilla we encountered.

I have a fondness for these plants especially the ones which make fairly neat clumps and I grow a selection of them. The plants I grow are labeled Tunilla corrugata, Tunilla erectoclada, Tunilla microdisca, Tunilla soehrensii, and Tunilla tilcarensis as well as a selection of others labeled  Tunilla sp. to cover those which have arrived unlabelled,  have never flowered and  will  probably remain  unidentified. I  was quite  interested  to see how they would appear in habitat and the promised list of plants to be seen on the trip included four of the above.

We were fortunate enough to see the plants at several disparate locations and in differing habitats as well as in different stages of their growth cycle ranging from plants at rest (and looking very sorry for themselves) to plants actively growing and eventually in flower. They were seen on steep rocky hillsides, amongst small shrubs and grasses, on the more rolling grassy hillsides of the Puna but always at higher altitudes.

The plants are described in the date order we saw them and where the plant was not identified I have left them as Tunilla sp. I would be very interested if other members of the TSG are able to suggest names for these – and indeed if they disagree with any of the names allocated to the plants.

The first plants we saw were on day three of the tour on a mine road which leads north out of Famatina in La Rioja province, Argentina. We negotiated this dirt road for some miles out of the town, crossed an almost dry river bed strewn with moderately sized boulders (no mean feat in a mini bus – 10/10 for the driver) and toiled up the road on the far side until Willy called a halt on top of a narrow ridge. We were at around 2,200m here and the scenery was spectacular with steep hillsides covered with low thorny scrub and tufts of coarse grass (fig. 1).

Fig. 1

Fig. 1. North of Famatina in La Rioja province, Argentina. Approx. 2,2000m.

The Tunilla which we saw here were introduced to us as T. corrugata (fig. 2). They were very desiccated with numerous dead and detached segments and few signs of new growth, flowers or seed pods. They grew in association with Denmoza rhodacantha and Soehrensia formosa which, having much larger bodies, were coping with the lack of rain far better than were the Tunilla. We searched the area for other plants and eventually found a few small clumps of Tephrocactus weberi which were showing some buds but they were not in good condition and also failed to inspire much enthusiasm amongst the group.

Fig. 2

Fig. 2. Tunilla corrugata at the above location

There were no Tunilla to be seen on our excursion into Chile and it was not until day nine when we crossed back over the Andes into Argentina and began to drop down the eastern foothills into Jujuy province that we encountered more of these plants. We were some 350 miles further north than the first location where we had seen them and somewhat higher in elevation but the landscape was similar overall.

The first stop this day was at a location Willy referred to as ‘Aguas Blancas’  – (a name which seemed to crop up regularly) and the Tunilla species we encountered was not one of the listed plants for this location.

The hillside we explored was steep and strewn with rocks of varying size and covered for the most part by low growing thorny shrubs (fig. 3). The Tunilla grew alongside Cumulopuntia boliviana, Soehrensia formosa and some unknown Lobivia. They were all very well spined plants and quite plump but there were no plants in flower nor any sign of seed pods (fig. 4). Tunilla soehrensii was proposed as a name for these plants (originally shown on the front cover).

Fig. 3

Fig. 3. Hillside at Aguas Blancas, Jujuy province, Argentina

Fig. 4

Fig. 4. Tunilla soehrensii at the above location

Front Cover

Tunilla soehrensii at Aguas Blancas, Jujuy province, Argentina
(originally on the journal cover)

An hour later and slightly lower down the mountainside we stopped again at Cuesta de Lipan. This is a very spectacular section of road with numerous hairpin bends and very steeply sloping hillsides (fig. 5). We walked out across a ridge covered with tufts of yellow grass, small  boulders  and  the  occasional  small shrub.  The  Tunilla  here  had  quite differently coloured spines than the earlier plants, these having a reddish colour when young and fading to almost white when mature (fig. 6). There were a variety of other cacti dotted across the hillside namely: Oreocereus trollii, Soehrensia formosa, Lobivia marsoneri and Cumulopuntia boliviana.

Fig. 5

Fig. 5. Cuesta de Lipan

Fig. 6

Fig. 6. Tunilla sp. at the above location.

There was a further gap in the sighting of Tunilla until day twelve when we worked our way south and west from Salta back up into the mountains heading towards Cachi. The scenery was as spectacular ascending as it had been descending three days earlier.  We were back up to around 3,400m here and the terrain was a series of low undulating hills (fig 7). It was cloudy and cold where we stopped and the vegetation was composed of grasses and lichens reflecting the damper atmosphere.

Fig. 7

Fig. 7. South West from Salta towards Cachi. Approx. 3,400 m

The plants were unidentified and remain as Tunilla sp. in my notes (fig. 8). They grew alongside Cumulopuntia boliviana, Rebutia nigricans and Lobivia haematacantha v. kuehnrichii. Large sprawling clumps of Austrocylindropuntia  (now Tephrocactus) verschaffeltii were also in evidence – showing the same tendency to shed segments that they do in cultivation.

Fig. 8

Fig. 8. Tunilla sp. at the above location

We progressed across the plain under an increasingly heavy sky and eventually stopped at the viewing point at Payogasta and wandered down the hillside to view a varied selection of plants including Trichocereus pasacana, Tephrocactus weberi, Opuntia sulphurea, Gymnocalycium spegazzinii and large clumps of what was suggested as Tunilla erectoclada (fig. 9).

Fig. 9

Fig. 9. Tunilla erectoclada at Payogasta

We then spent a couple of days heading back to Salta not seeing any Tunilla and I assumed that there were not going to be any further opportunities to view them. However on the last day of the trip we drove west out of Salta along Route 51 and back up onto the Puna towards Inca Huasi (another one). At a height of around 3,500m beside a cold clear stream (fig. 10) we found a very well spined Tunilla and this time with flowers (fig. 11). The other members of the group showed little interest but to me this was a wonderful find and having found one I walked up the rocky hillside and soon found several more. They were growing with Trichocereus pasacana and a very long spined Lobivia. Tunilla tilcarensis was put forward as the name of these plants.

Fig. 10

Fig. 10. Near Route 51 west of Salta towards Inca Huasi. Approx. 3,500m

Fig. 11

Fig. 11. Tunilla tilcarensis at the above location

I collected seed at a couple of locations and to my surprise they germinated quite rapidly and grew away well to look absolutely nothing like their parents. Having not succeeded in germinating them before I am assuming that the mature spination and segment shape will come with age but the seedlings at present are fairly cylindrical and covered with a short ‘down’ of spines.

In conclusion I will have to finish with the observation that if the Tunilla are difficult to identify in cultivation they are doubly difficult in habitat. There seems to be a very wide range of spine length and colouration amongst plants which are probably the same species and I would not be 100% certain of most of the plants we saw. Hindsight being a wonderful thing I wished I had brought full descriptions of the species with me to act as a guide but I am not sure it would have really helped – especially with the desiccated plants where the true shape of the segments was lost under a dense covering of spines.  

This article was originally published in Tephrocactus Study Group (the 'TSG Journal'), March 2010, Vol. 16, No. 1, pages 2-10. © TSG and Mike Partridge