Born from a few areolas

By Piotr Swiatoniowski.

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There are not many Opuntias, which seems to need grafting as a method of propagation. Almost all of these hardened plants form new roots from single cutting without any problems. For a very long time, A.malyana was regarded as incapable to cultivate without grafting, but even this fallacy appeared to concern particular clone.Though, there are also such species like almost always solitary Austrocylindropuntia pachypa, that become one of the most difficult to obtain for this, unusual among the Opuntioideae family, reason. This magnificent species from Chosica Vallay in Peru is a funny exception to the general role of segmentation.

In this particular case and in some other slow growing Opuntias, grafting a part of peel with just a few areolas is the desirable solution. This type of grafting, which requires very little stuff, is usualy impossible to carry out with most cacti, but in case of our favourite Opuntias it is unbelievably easy. Many cacti growers would be very satisfied if Geohintonia mexicana, Mammillaria pectinifera and other mexican rarities were possible to propagate by this way.
I have propagated a few slow growing species like Pterocactus hickenii f.skottsbergii and mentioned earlier Austrocylindropuntia pachypa using this method and I would like to present some of my observations.

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A "peel" of Austrocylindropuntia pachypa grafted on Opuntia ficus-indica. 2 of 3 aerolas have just started to grow.
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A "peel" of Austrocylindropuntia pachypa grafted on Echinopsis eyriesii just after beginning of activate new groth.

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A young plant of Austrocylindropuntia pachypa obtained from a "peel" that is still visible on the stock (O. ficus-indica).
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A young "peel" plant of Austrocylindropuntia pachypa grafted on O. ficus-indica. The "peel" is just visible at the base.

Austocylindropuntia subulata and Austrocylindropuntia cylindrica seems to be one of the most popular stock for other Opuntias. It is not the best one, though, if we are going to graft a piece of peel. Because there are no growing points on the graft, the common stock gives many offsets that cramp proper growth. In connection with this feature, the sleeping areolas of the slower growing graft lose emulation of priority to activate growing point with much faster growing areolas of the stock. The following result bring about reduction, or even inhibition of the growing process. Of course, someone can try to cut out most areolas of the stock, that usually gives good effects, but spoils plant's beauty at the same time.

I would like to recommend Opuntia ficus-indica as a competent stock for a few reasons. This well known species, similarly to most Opuntias with flat segments, has got this special attribute that after grafting it shoots out new branches very seldom. What is more, Opuntia ficus-indica accrete with the graft very easily and can live on for many years. Flimsy resistance for the cold appear to be the only weakness of this stock. However, Austrocylindropuntia subulata is not frost-hardy either. According to my winter experiences, some clones are very sensible to stagnant cold and they freeze to death in temperature lower than 4C.

The main idea of my method is quite simple. At first we have to obtain a "peel" from a plant, that we would like to propagate by using a razor blade. Then, we have to trim the strip by slicing from the strip some of the parenchyma, leaving about 3-3.5mm of the soft tissue under the epidermis. At this stage the vascular bundles (which go from the main central vascular bundle strip to each areole) of every areole on the peel, can be seen. Thus these vascular bundles can link up to those on the stock and the "sleeping growing points" hidden in the mature areoles can become active.

It is important to remember that only fully developed areola can form a characteristic segment. One should realize that the peel from the undeveloped part of the plant won't be able to shoot out a proper joint, as it happens with undeveloped cuttings after taking roots. This quite striking phenomenon existing as well in case of Austrocylindropuntia as other related genera seems to require individual discussion.

The grafted fragment of Austrocylindropuntia pachypa needs a few weeks to start growing, but after this time we will be able to enjoy our new plant. Please, look at the pictures and try to propagate your own specimens !

In addition, I would like to mention that I have grafted much larger piece of Austrocylindropuntia pachypa on Hylocereus undatus. Unfortunately, it turned out that this fast growing stock is not proper for this Opuntia. The new segment is quite untypical with symptoms similar to poverty of light. What is interesting, the graft required much more time to strat growing and it wasn't as fast as I had suspected. Actually, the graft was developing extremly slow. There have to exist some important distinctions beetwen growing hormons. Perhaps it is connected with the alkaloides which were found in Austrocylindropuntia pachypa, but weren't reported in Hylocereus undatus.

The following experiment with grafting Austrocylindropuntia pachypa on Pereiskiopsis spathulata didn't succeed for some reasons.

Special thanks to Roger Moreton, who has kindly send me Austrocylindropuntia pachypa.
This article has been first published in the Tephrocactus Study Group journal.

E-mail-Piotr Swiatoniowski
Text & photos : Piotr Swiatoniowski

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