Plant & Flower Identification

Identify San Pedro Cactus – 6 Points You Should Notice

Are you intrigued by the distinctive beauty of cacti plants and eager to explore their unique species? 

Look no further than the San Pedro cactus. Its distinct appearance makes it a fascinating subject for plant enthusiasts and those interested in traditional medicine and shamanic practices.

In this guide, I will focus on how to identify San Pedro cactus.

By familiarizing yourself with the distinguishing features of the San Pedro cactus, you will develop the ability to recognize and appreciate this captivating species within the vast world of cacti.

What Is San Pedro Cactus?

identify san pedro cactus

The San Pedro cactus is scientifically known as Echinopsis pachanoi or Trichocereus pachanoi. This columnar cactus is a member of the Cactaceae family.

Its origin is from the Andes Mountains region of South America. Its native range includes Peru, Ecuador, and Colombia, where it has been growing naturally for centuries.

This cactus is known for its tall and columnar growth habit, often reaching heights of 3 to 6 meters (10 to 20 feet) or even taller.

Its main stem or trunk is green and ribbed, with clusters of sharp spines along the ribs. The cactus may also develop multiple branches or “arms” that grow from the main stem.

The San Pedro cactus has a rich cultural history and has been used for centuries by indigenous communities in traditional medicine and shamanic practices.

It contains various alkaloids, notably mescaline, which is a psychoactive compound.

The cactus is known for its potential medicinal properties and is still used today in certain traditional rituals and ceremonies.

In addition to its cultural significance, the San Pedro cactus is also appreciated for its ornamental value.

This species is grown by cacti enthusiasts and collectors for its unique appearance and ability to thrive in arid climates.

How To Identify San Pedro Cactus

san pedro cactus identification

To identify a San Pedro cactus, look for its vibrant green color, columnar shape, pronounced rib structure, long spines, large white flowers, and branches that may grow from the main stem.

Now, let’s dive deeper into the outstanding characteristics of this cacti variant!


While you can identify fruit trees by leaf, identifying San Pedro cactus can start by examining its ribs.

First, count the number of vertical ribs running along the stem, typically ranging from 4 to 8, with 6 to 7 being the most common. 

Its ribs are evenly spaced apart and have a pronounced depth, creating ridges along the stem.

The texture is usually smooth and may be slightly waxy or glossy.

However, it’s essential to consider other features such as spines, overall shape, flowers, and growth pattern to confirm the identification and consult additional resources if needed.


This cactus plant’s areoles are also a notable characteristic. You may observe the spiral arrangement of small, raised structures along the ribs.

These areoles serve as the points from which clusters of spines and sometimes hairs emerge.

Look for multiple spines per areole, varying in length and color, and pay attention to the presence of any wool-like hairs.

Considering the placement, spine formation, and potential hair presence on the areoles can assist in identifying the type of cactus plant.


Next, observe the stem’s predominant hue. Typically, this type of cactus has a vibrant green coloration. However, younger plants may exhibit a bluish-green tint.

It’s important to note that the exact shade of green can vary depending on factors such as sunlight exposure, age, and growing conditions.

By noting the characteristic green color, you can help distinguish the cacti.


Inspect clusters of cactus spines along the ribs.

San Pedro cacti usually have sharp spines that can vary in length and color, ranging from short to several centimeters long. These spines serve as a protective feature.

San Pedro cacti typically have multiple spines per areole, which may be straight or slightly curved.

You should take note of their arrangement and distribution along the ribs and their overall appearance.


This cactus’s blooming season is in spring or early summer.

Observing these distinct flowers’ presence, color, shape, fragrance, and blooming timing can help recognize the San Pedros.

Typically, San Pedro cacti produce large, showy, white flowers. The flowers are funnel-shaped and emit a sweet fragrance. They often open at night to attract pollinators such as moths.


Next, you should keep an eye on the growth pattern and the presence of additional arms or offshoots.

San Pedro cacti may develop multiple branches or “arms” that grow from the main stem.

Look for the emergence of these additional arms, noting their size, angle of growth, and overall symmetry.

These branches can add to the overall height and volume of the cactus.

San Pedro Cactus Look Alikes

how to identify san pedro cactus

Cereus Repandus

Cereus Repandus is commonly known as the Peruvian Apple Cactus or the Hedge Cactus.

This species is native to South America. It may also share some similarities in appearance with the San Pedro cactus.

While both the San Pedro cactus and the Peruvian Apple Cactus have columnar growth habits and ribbed structures, they belong to different genera within the Cactaceae family.

The San Pedro cactus belongs to the Echinopsis or Trichocereus genus, while the latter belongs to the Cereus genus.

The Peruvian Apple Cactus is characterized by its tall, columnar shape with vertical ribs and large, spiny clusters that protrude from the ribs.

It can grow up to 10 meters in height. Their flowers are white or pale yellow.

Pilosocereus Pachycladus 

Pilosocereus Pachycladus belongs to the Pilosocereus genus, which is part of the Cactaceae family. It is commonly known as the “Blue Torch” or “Blue Columnar Cactus.” 

The Pilosocereus Pachycladus and the San Pedro cactus have some traits in common.

They include their columnar growth habit and cactus characteristics. Yet, these two cacti belong to different genera within the Cactaceae family.

Pilosocereus Pachycladus is regcognized by its tall, columnar growth habit, bluish-green to blue-gray coloration, and closely spaced vertical ribs.

It typically has fine spines or bristles covering the ribs and yields large, nocturnal flowers, usually white or cream-colored.

Myrtillocactus Geometrizans 

Myrtillocactus Geometrizans, commonly known as the Blue Candle or Bilberry Cactus, is a species of cactus native to Mexico.

It belongs to the Cactaceae family and is characterized by its columnar growth habit and blue-green coloration.

Myrtillocactus Geometrizans and the San Pedro cactus may share certain similarities, such as their columnar growth habit and cactus characteristics.

But they are distinct species belonging to different genera.

The Blue Candle cactus has a tall, upright stem with vertical ribs that are often segmented. The stem can reach impressive heights, sometimes exceeding 6 meters (20 feet).

Their spines are short, stout, and typically arranged in clusters along the ribs. They may be yellowish or reddish-brown in color.

Moreover, the Blue Candle produces small, greenish-yellow flowers that bloom at the upper portion of the stem.

The flowers are followed by small, berry-like fruits that can range in color from green to purple when ripe.

These ripe fruits are edible, just like ripe cactus pear or prickly pear.

These are the primary differences between them!


In conclusion, if you want to identify San Pedro cactus, you should examine various characteristics such as its rib structure, areoles, color, spines, flowers, and branches.

By closely observing the unique traits of this amazing cactus and comparing them to reliable references, one can confidently identify this remarkable cactus species.

Proper identification ensures accurate cactus care and appreciation of its distinct qualities.

Samuel Mark

Hello I am Samuel. Samuel's Garden is a garden blog where I share my experiences in garden caring and tree growth. Hope you enjoy it!

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  1. Hey Samuel! Thanks a lot for your article. I’m having a cactus at home and still not sure of the type. I did try to turn it into tea, but no psycho effect, only a bit of numbness and detachment.

    Would you mind having a look at the pics if I send it to you ? curious to have your opinion.

    Thanks a lot again !

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