Jump to content
The Corroboree
  • 0
M S Smith

On T. pachanoi, T. peruvianus, and T. macrogonus

Question

Here's something I threw together over the last day or two. It is more or less a repeat of some of the stuff I've said before, but I tried to put it in a little more order. I hope everyone likes it and finds it useful.

~Michael~

********

On T. pachanoi, T. peruvianus, and T. macrogonus

By Michael S. Smith

March 16, 2008

For years the plant in the following photo has gone by the name Trichocereus pachanoi and is widely known as the "Backeberg clone," apparently without clear support that this particular clone was introduced into US cultivation by Backeberg himself. This plant is particularly consistent in its growth habit and appears to be a true “clone” as it is unable to crossbreed with other matching its characteristics, thereby revealing that it is of a singular genetic make-up and a plant widely propagated through clippings. It has been the common form of T. pachanoi for decades, most likely due to its particularly hardy nature in the American southwest, the region from which it appears have had its origins into general cultivation. In the last few years there has been an increase in the importation of T. pachanoi from Ecuador and Peru, none of which match this clone. I have seen little support that the so-called "Backeberg clone" grows in Ecuador or Peru as a native and historically present plant, but it is likely present there now to a small degree in collections.

I have recently suggested that the so-called “Backeberg clone” is in fact a closer relative of T. bridgesii than to the T. pachanoi of Ecuador and Peru. This needs to be explored further, but will likely need to await genetic tests.

TpachHN017.jpg

Next is a somewhat typical T. pachanoi of Ecuador and Peru. This form of T. pachanoi is ubiquitous from Ecuador through Peru and to a smaller degree in Chile and northern Bolivia. It appears to have a much more prominent place in Ecuador and northern Peru than in the dryer conditions farther south. Spine length on this form can be quite variable, but the general rib formation remains fairly consistent.

TperuKK242_Tpach005.jpg

Below is the so-called "short spined T. peruvianus." This name appear to be completely of my own doing when many years ago it was sent to me simply as a “T. peruvianus” and I added the "short spined" moniker to differentiate it from the then common long spined form of T. peruvianus that I have more recently suspected is T. cuzcoensis. This particular "short spined T. peruvianus" is clearly a form of T. pachanoi.

The “short spined T. peruvianus” may have had its source from the Berkeley Botanical Garden as it appears to be identical to their “Trichocereus sp. Peru #64.0762” which was collected by P. Hutchinson and J.K. Wright at the Canyon Rio Maranon above Chagual, Huamachuco Province, Peru.

TperuShortSpinedCactusCorral040.jpg

As said before, the T. pachanoi of Ecuador and Peru can be quite variable dependent upon genetics and breeding in different ranges, but this is almost solely in regards to spine length. Some T. pachanoi are mistakenly regarded as “short spined T. peruvianus” due to some considering the so-called “Backeberg clone” the standard T. pachanoi. I should note again that the “short spined T. peruvianus” is better understood as a T. pachanoi and not a T. peruvianus.

Below is the plant I consider an accurate representation of T. peruvianus. This plant is common in Department Lima, Peru, and in particular near the town of Matucana, the location assigned to the species by Britton & Rose. Like with T. pachanoi there is a range of variability in growth habit, particularly in spination, but also in regards to it being erect or decumbent. It is also much more glacous (“frosted”) than T. pachanoi, in all likelihood due to its location in the dryer south (glaucescence appearing to serve as a sort of reflective sunscreen for the plant).

TperuvianusBS007.jpg

This T. peruvianus is quite distinct from the plant below which I refer to as “T. peruvianus (T. cuzcoensis?)” and which was a common T. peruvianus in cultivation since the early 1990s and was said to come from Matucana, Peru, and often went by the collection number KK242 of Karol Knize.

Tperuvianus-cuzcoensisQ1.jpg

This “T. peruvianus (T. cuzcoensis?)” plant does not appear to be represented in the Matucana region, but it does quite accurately match plants from Department Cuzco, Peru, the location of T. cuzcoensis. Hopefully at this point it should be needless to say that the T. cuzcoensis of the Cuzco region, like T. pachanoi and T. peruvianus, also shows degrees of variability.

Lastly, here are a few pictures of plants commonly referred to as T. macrogonus. The first two are of the same plant.

TmacrogonusOsprey003.jpg

TmacrogonusOsprey005.jpg

TmacrogonusKohres005.jpg

TmacrogonusSAB.jpg

TspRS0004_003.jpg

It is interesting to note the similarities between the T. pachanoi of Ecuador and Peru, the T. peruvianus of Lima, and T. macrogonus. If you look closely they are somewhat upon a sliding scale, with the T. macrogonus appearing to be an intermediary between the T. pachanoi and the T. peruvianus. These three no doubt bear flowers that upon dissection would show them to be the same identical species, therefore the name of these three should be the species that was first named and described. T. macrogonus has the oldest name, but due to the confusion regarding it, and the fact that it was described from a plant in a European collection that lacked collection data, the species name should be either T. pachanoi or T. peruvianus. But this is confounded by the fact that these two were both described as “Species Nova” (“New Species”) by Britton & Rose without comment regarding which was described first. So in the end the overarching species should be called one of these two names alone. Regardless of this botanical understanding maintaining the use of two names is valuable when trying to speaking about plants that fit a certain type, and therefore whether you call a plant T. pachanoi or T. peruvianus, seeing that the main difference is in spination, is dependent upon the length of the spines. Plants that fall somewhere in-between seem to be quickly regarded as T. macrogonus, but there is nothing that points towards T. macrogonus being any different than T. pachanoi or T. peruvianus with the exception that it has spination somewhat intermediate between these two main species.

Well I hope that helps a little bit and isn’t too confusing. I’m sure those who are students of these plants will take something from it, but please note there is nothing definitive about my opinions and they will require further research from those in a better position than I.

Edited by M S Smith
  • Like 4

Share this post


Link to post
Share on other sites

Recommended Posts

  • 0

You've caught the cactus bug and I don't mean the infections on your plants!

 

The wrinkling and yellowing at the base is normal for cactus seedlings. The base may have been below the soil line so the chlorophyll production may be reduced and now its exposed to the sun will green up again, and the wrinkling is just a consequence of growing from a tiny thing into a slightly less tiny thing. It will grow out.

 

It seriously looks fine to me.

 

Trichos are super forgiving, rich but well draining organic soil has worked best for me, i never bothered to do anything special for them. the mix you made sounds good for picky cactus but trichos are not in this category. I found the type of soil you describe can actually impede their growth. I have found large chunks of coir in mixes to be extremely counter-productive.

 

Re: smaller pots you definitely don't want to encourage root binding, that is bad for anything. but if you think of your little plant its roots are sitting in an ocean of soil, there's not much stability there and the soil around the root ball may stay wet and cause the fine hairs at the ends of the root tips to rot, so the plant never grows and feels disinclined too. You could easily grow four same sized seedlings in a pot that size and they will grow as fast or faster and save you room (them do seem to like to grow together at first). ime a pot with enough room to fill out over one growing season, ready for repotting in the next season, is about right. eventually a large plant can be plonked into big pot, but especially at this age, smaller is better.

  • Like 1

Share this post


Link to post
Share on other sites
  • 0
2 hours ago, Micromegas said:

You've caught the cactus bug and I don't mean the infections on your plants!

 

The wrinkling and yellowing at the base is normal for cactus seedlings. The base may have been below the soil line so the chlorophyll production may be reduced and now its exposed to the sun will green up again, and the wrinkling is just a consequence of growing from a tiny thing into a slightly less tiny thing. It will grow out.

 

It seriously looks fine to me.

 

Trichos are super forgiving, rich but well draining organic soil has worked best for me, i never bothered to do anything special for them. the mix you made sounds good for picky cactus but trichos are not in this category. I found the type of soil you describe can actually impede their growth. I have found large chunks of coir in mixes to be extremely counter-productive.

 

Re: smaller pots you definitely don't want to encourage root binding, that is bad for anything. but if you think of your little plant its roots are sitting in an ocean of soil, there's not much stability there and the soil around the root ball may stay wet and cause the fine hairs at the ends of the root tips to rot, so the plant never grows and feels disinclined too. You could easily grow four same sized seedlings in a pot that size and they will grow as fast or faster and save you room (them do seem to like to grow together at first). ime a pot with enough room to fill out over one growing season, ready for repotting in the next season, is about right. eventually a large plant can be plonked into big pot, but especially at this age, smaller is better.

I have noticed that out of ten different Trichos I potted a month ago, in this manor; a little more than half of them are swelling nicely but there seems to be a few that are stalled.  

I've definitely have read some negative things about chucky coir. Next time I pot up I'll probably leave that out and find taller pots as oppose to wider, like you say.

My first cacti were hardware store trichs. And not knowing any better I put then in straight potting mix very little perlite. Had them outside in that for  most of a Canadian summer season absolutly loving it. Until the weather started changing or it rained too much, cant remember. Didn't know enough about succulent care. And it was a sad slow death. Just to add to what you are saying that trichs can take alot of abuse. 

Wish I had pictures.

Cheers

  • Like 1

Share this post


Link to post
Share on other sites
  • 0

Yeah it's a fair point. what works in one climate may not in another. i don't live anywhere particularly wet or cold so i didn't consider a different climate may need different soil. trial and error is the best method to find out of course and sounds like you're on to it. strictly this thread is for id'ing some various types of trichocereus. there's heaps of growing advice on the forums. happy gardening!

Share this post


Link to post
Share on other sites
  • 0

Ya for sure

That's why I posted a picture of a pachanoi Juul's / macrogonus x bridgesii yearling incase people are growing mystery seeds and need some help IDing.

  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×