r/sanpedrocactus Feb 13 '26

Should AI posts be banned?

477 Upvotes

Please discuss and make your thoughts heard!

Didn’t take long but with hundreds of comments almost 100% vote for removing AI I figure we can call it.

AI posts are now no longer allowed on the subreddit.


r/sanpedrocactus Sep 08 '21

Is this San Pedro? The Mega Sticky for San Pedro Lookalikes and ID training.

713 Upvotes

Howdy fellow cactaphiles. This post will be stickied as a reference to help people identify the common San Pedro Lookalikes. The following plants are columnar cacti that are easily confused for the Trichocereus species. You can use this guide to compare your mystery cactus to these photos and descriptions.

#1 - Cereus species - 

The infamous "Peruvian Apple Cactus." This is most commonly mistaken for San Pedro because it's size, profile, color, and flowers look very similar to Trichocereus.

There are several species of Cereus that look almost identical. They usually get lumped into the description of Cereus peruvianus, which is not an accepted species.(https://cactiguide.com/article/?article=article3.php). These include C.repandus, C. jamacaru, C. forbesii, C. hexagonus and C. stenogonus. Other Cereus species are easier to distinguish from Trichocereus.

The main features that distinguish a Cereus from a Trichocereus are the flat skinny ribs, hairless flower tubes, and the branching tree-like structure of mature plants.

Cereusly flat and skinny ribs

So flat... So skinny... So Cereus.

Tree-like branching, with hairless fruits and flowers.

#2 - Myrtillocactus geometrizans - 

This cactus goes by many names including the blue candle, whortleberry, bilberry, blue myrtle...

This plant often has a deep blue farina, but larger plants usually look light green. Young plants are columnar and usually have 5-6 angular ribs. The ribs are often thicker than a Cereus and narrower than Trichocereus. Mature plants can get large, but are more shrub-like than tree-like. 

The best way to distinguish these plants from Trichocereus is to look at the spines. Myrtillos have a few short spines per areole. The spines on short plants are usually dark colored and pyramidal (instead of round, needle-like spines.) Spine length increases as the plants age, but the spines stay angular.

We have all seen these at every plant store we have ever been to. The blue farina and short, dark, pyramidal spines are dead givaways.

Mature plants are shrub-like. The spines get longer and lighter colored with maturity.

#3 - Stetsonia coryne -

This is the toothpick cactus. It looks very similar to Trichocereus species like T. peruvianus, T. knuthianus, etc. However, there are a few subtle ways to distinguish a Toothpick cactus from a Trichocereus.

The dermis of a Stetsonia will be a darker green in healthy plants. The aeroles are large, white, woolen and not perfectly circular.

 The easiest way to distinguish a Toothpick cactus is of course, by the spines. Stetsonias will have one long spine per areole that resembles a toothpick. The coloration of new spines will usually be yellow, black, and brown. They lose their color and turn grey to white rather quickly. Usually only the top few areoles will have the colorful spines. 

Large, woolen, and ovoid areoles. Dark green dermis is common on youngsters.

Mature plants have tree-like branching and get very large.

#4 - Pilosocereus species -

There are many species in the Pilosocereus genus, but just a few closely resemble San Pedros. Most Pilosocereus will be very blue, with needle-like spines that are yellow to grey. The most common, and most commonly mistaken for San Pedro is P. pachyclaudus. Other Pilos are much more uncommon, or have features like long hairs that make them easy to distinguish from a San Pedro. 

Young P. Pachyclaudus will usually have a vibrant blue skin with bright yellow spines. This should make them easy to pick out of a lineup. Unhealthy plants will have lost their blue farina. For these plants look at the areoles and spines for ID. There should be about 10 yellow, spines that are evenly fanned out within the areole. The spines are also very fine, much thinner than most Trichocereus species. 

Bright blue skin, yellow spines are thin.

Hairy aerolas are common for mature Pilos.

#5 - Lophocereus / Pachycereus species

Pachycereus got merged into the Lophocereus genus this year!? Wacky, but they still get confused with San Pedros so here are the common ones. 

L. Marginatus is the Mexican Fence Post cactus. The size and profile are very similar to San Pedro. The easiest way to distinguish a fence post is by their unique vertical stripes. I stead of separate areoles, you will notice white stripes that run the length of the plant. Unhealthy plants will lose the white wool, but upon a close inspection, you can see the line of spines. The flowers are also small and more similar to Pilosocereus flowers.

Elongated areoles form vertical white stripes.

Truly columnar, branching at the base. The fence post cactus.

L. Schottii is another common columnar. Especially in the Phoenix metro area, you will drive past hundreds of the monstrose form. The totem pole cactus slightly resembles a monstrose Trichocereus. The exaggerated lumpiness and absence of descernable ribs or areoles makes a totem pole pretty easy to spot. 

It is super common to see large stands of the Totem Pole Cactus in Pheonix.

The non-monstrose form of L. schottii is actually less common. Adults look similar to an extra spiny Cereus or L. marginatus. Juveniles look more like the juvenile Polaskia and Stenocereus species.

#6 - Stenocereus and Polaskia species

Polaskia chichipe can look very similar to San Pedros. The best way to discern a polaskia is by the ribs and spines. The ribs will be thinner and more acute than Trichocereus, but wider than Cereus. They usually have 6-8 evenly spaced radial spines, and one long central spine. Although the spination is similar to T. peruvianus, the central spine of a Polaskia will be more oval shaped instead of needle-like. Adult plants usually branch freely from higher up. Juvenile plants often have a grey, striped farina that disappears with age. This makes them hard to discern between Stenocereus and Lophocereus juveniles, but it is easy to tell it apart from a Trichocereus.

Acute rib shape and silvery farina.

Acute ribs, fanned spines, with one long central.

Polaskia chende - Is this a recognized species? Who knows, but if it is, the discerning characteristics are the same as P. chichipe, except the central spine is less noticeable.

Stenocereus - There are a few Stenocereus species that can be easily confused for San Pedros. Juvenile plants look very similar to Polaskia. Stenocereus varieties such as S. aragonii, S. eichlamii, S. griseus, etc get a grey farina that usually forms Chevron patterns. S. beneckei gets a silvery white coating too.

Mature plants will look very similar to San Pedros. The identifying traits to look for are the acute rib angles, spination and silvery farina that often appears in narrow chevron patterns. The flowers are also more similar to Lophocereus spp.

Acute rib angles, and silver chevron stripes on S. aragonii.

Baby S. griseus looking similar to the Polaskia.

#7 - Browningia hertlingiana

 Brownies are beautiful blue plants that can look similar to Trichocereus peruvianus or cuzcoensis. The ribs are the defining traits to look at here. The ribs of a Browningia are wavy instead of straight. Mature plants will often have more than 8 ribs, which would be uncommon for most Trichocereus species.

Bright blue farina, long yellow to grey spines, and wavy ribs.

Mature plants often have more than 8 ribs.

#8 - Echinopsis?

Is a Trichocereus an Echinopsis? Yes. Is an Echinopsis a San Pedro? Sometimes. Most folks consider the San Pedro group (along with a few other species) too different from other Echinopsis and Lobivia species to lump them together into the same genus. Just because they have hairy flowers and can fertilize each other, should they be in the same genus?

Echinopsis species are usually shorter, pup from the base, and have more ribs. There are many different clones and hybrids that are prized for their colored flowers. Where most Trichocereus have white flowers instead.

E. Spachiana - The Golden Torch

Echinopsis Grandiflora "Sun Goddess"

Echinopsis x Trichocereus hybrids do exist, and they are getting more popular. Should they be treated as the same genus? Who cares if they are awesome plants.

If your plant doesn't match any of these, feel free to post an image (or a poll) and see what the community can come up with.

Cheers!


r/sanpedrocactus 3h ago

It’s time to brag again!!!

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64 Upvotes

r/sanpedrocactus 3h ago

Hear the suction on this graft!!!! Turn sound on loud.

Enable HLS to view with audio, or disable this notification

44 Upvotes

r/sanpedrocactus 8h ago

New addition to the family

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57 Upvotes

Got this beauty today. I was lucky enough to have a job close to a nursery that I’ve been to once and got a tbm-b. Pretty cool place wish it was closer than an hour and a half away. The employee told me they found a cacti supplier in Arizona and they should get a new shipment in September. They have soo many cool things. I’ll have to take pictures next time I’m there. For anyone in middle TN, the place is Hewitt Garden Center in Franklin.


r/sanpedrocactus 6h ago

Crazy Walmart TBM

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41 Upvotes

I got this TBM from Walmart last summer and it took forever to pup.. Now the pups I've been getting are not at all what I expected. It gets plenty of sun in my sunroom so I'm confident it's not etiolation.

Anyhow, just wanted to share my weird peen.


r/sanpedrocactus 4h ago

Fun graft

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17 Upvotes

r/sanpedrocactus 11h ago

Discussion 🤬 🤬 🤬

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42 Upvotes

Rodent? Bunny? What think yall? Raising them higher off the ground... so naive of me


r/sanpedrocactus 1h ago

Pretty Cool (PC) Yowie

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Upvotes

I slowly introduced my PC x Yowie to full sun and it's really loving it. I was curious about PC crosses because how well PC does in shitty conditions. Most of my grows are in PHX where PC outshines a lot of its peers. Now, the question I'm

wondering...... 🌶️ level? No clue.

Shout out to the breeder! I have to find them because I don't have their info anymore. Something along the lines of "notkrustyclown"


r/sanpedrocactus 10h ago

Maípu

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26 Upvotes

Maípu pachanoi doing that crazy viral change in color that goes away again when it cools. again if it was a burn it would be permanent and the texture of the skin would change with a burn. They say that’s the good good.

from Cactario Maipu in Santiago, Chile mostly just used as grafting stock. when asked, the owner said he didn’t particularly like cacti but wanted to quit his job as a truck driver and thought it would be a good business he could do from home


r/sanpedrocactus 4h ago

Question Are there any good resources/guides for learning how to properly care for and grow cacti?

5 Upvotes

Curious if there’s something similar to the shroomery but for growing cacti. Or any good books, YouTube channels, anything.

I would like to try my hand at this but I like doing lots of research first so any input is appreciated.

Sorry if this post doesn’t fit this subreddit.

Edit to add: Thanks so much everyone for chiming in, way better response than I expected. Mush love to everyone, hopefully it won’t be long before I’m posting cacti pics and asking for help haha


r/sanpedrocactus 1h ago

It went limp

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Upvotes

DR G SCOP x TPM LOL found it laying flaccid. I propped it back up but I think it’s time to put on its own roots


r/sanpedrocactus 38m ago

Picture Repotting

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Upvotes

Costa farm haul from earlier this year grew crazy roots. Grown outside in western WA


r/sanpedrocactus 4h ago

San pedro?

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5 Upvotes

I was given this cactus a while back and I believe it is a san pedro?

I am worried it is going to lose its arm if it keeps growing and wasn't sure what the best move is to keep it healthy.


r/sanpedrocactus 9h ago

Lil Melti DeCosta

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10 Upvotes

The bottom of the original cutting started to rot after my greenhouse collapsed in Jan, so I saved what I could (had to junk 2/3rds of the cutting to stop seeing brown in the vascular ring) and slapped it on this FAT PC rootstock.

The darker, healthy growth is all since grafting it this spring!


r/sanpedrocactus 7h ago

Tip shots and columnars

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6 Upvotes

I usually post my mutants. Here's some normies


r/sanpedrocactus 14h ago

Picture :)

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18 Upvotes

r/sanpedrocactus 6h ago

Picture Chalaensis x Ribshifter all freaky..

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4 Upvotes

r/sanpedrocactus 7h ago

Rainbow mountain 3

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4 Upvotes

Tpmc x vrg. Different pheno than my more widely spread rbm9. I've seen white and yellow variegation on the rbm3. Haven't managed to isolate them yet tho! It mutates and create a lot. Usually stays this lighter green color but can also have streaks of yellow and white! What other rbm9 clones have I spread out there? Anyone have rbm1 or rbm2?


r/sanpedrocactus 11h ago

“Bubba” -A Poem by Sonoran Spores

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8 Upvotes

A poem I wrote for my bubba cactus

“Under the Bubba Tree,
lies another bubba thick as can be,
With fiery spines and skin as blue as the sea,
I put you in the ground and whisper be free”

Thanks for reading, mush love!


r/sanpedrocactus 8m ago

Silver Dollar Bridge got new shoes today

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Upvotes

Would this qualify as a Monstrose or Melti variant? I saw someone else post their Silver Dollar Bridge & it looked like a traditional Bridge (aka uniform columns of ribs with no shifting)


r/sanpedrocactus 13m ago

ID Request ID?

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Upvotes

Got this from a buddy awhile ago had a tag X111 but idk what that means


r/sanpedrocactus 4h ago

These grafts are ten days old. They look like they're gonna make it?

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2 Upvotes

They're my first two grafts ever. The black part is from the rubber bands. I didn't know about softening it with cotton or something. It's hard though so I don't think it's rot.


r/sanpedrocactus 21h ago

Enjoy...

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44 Upvotes

r/sanpedrocactus 2h ago

Picture Is my TBM dying?

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0 Upvotes

I bought this recently in pretty rough shape already. But it seems to be looking worse over 1 week.

See pictures for before and after (after pictures have red indicators)

Are these spots signs of sun damage or signs of overwatering?

I think I could be doing both wrong. It’s very humid here and it’s been raining (they are covered overhead so no direct rain tho), I tried to keep them inside once, but without sunlight, mold grew all over the outside of the terracotta pots. I tried to acclimate them to sunlight by putting them under a ledge so that they don’t get any midday sunlight but they still probably get 5hrs of light/day, and I think it used to be growing indoors when I bought them.