A citizen science project to study cannabis morphology

The goal of the CannaData project is to gather morphological data on Cannabis leaves from around the world.
We need high quality photos from YOU! See Example

How To Do It

1. Choose a mature leaf that has finished growing and is not abnormal in any obvious way.

2. Place the leaf under a heavy book for 10 minutes to get it as flat as possible, so that the leaf’s position does not affect the shape analysis. Take a high quality photograph under good lighting to capture the small details in the leaf.

3. Measure the leaf's dimensions and provide us with your plants strain and sex. These are the most important, but if known, other data such as the plant's height and growing environment would be very useful in order to relate leaf shape to other morphologic traits.

4. Please note, you are not required to submit any personal information. Because in some locations this plant is illegal, your privacy is our first priority.

Why do we need photos of your leaves?

There are a tremendous number of Cannabis genotypes on Earth, and we'd like to study as many as possible! We are seeking personal growers, breeders, farmers, and hobbyists all over the world to contribute to an online database of morphological data. Visual photographs of the leaves are crucial in this endeavor. No registration or identification is required to contribute.

What are we studying?

We are encouraging the public to submit Cannabis leaf data in order to aid in the study of morphologic differences between the commonly used Cannabis strains, if they exist. Even though we are uncertain of the number of Cannabis species and we are unsure we can find pure accessions because most of the plants have been hybridized, our goal is to establish whether true differences in leaf shape between the frequently used plants occur. We hope to validate common assertions about differences in shape between Cannabis strains.

The inability to obtain pure wild accessions could prevent us from establishing the real variation between the species, however we will be able to determine shape variation between commonly used plants. We would also like to include leaves from Hops (Humulus), which is the closest relative to Cannabis in order to understand how the shape of these two related species has changed since their divergence time.

View Public Database

What do we expect to see?

We predict that there will be a difference between morphological traits of different Cannabis strains. By gathering quantitative data on these differences, we will better understand the number of Cannabis species. We hope to establish whether true differences in leaf shape between the common plants occur and to validate common assertions about differences in shape between Cannabis species.

How will we analyze the data?

These pictures will be analyzed using the program TPS Dig2 (Rohlf 2008), which allow us to place landmarks, or specific points in locations found in all of the individuals. Using statistical methods such as a Procrustes and Principal Component Analysis, we will establish whether the shape, determined by all of the landmark points differ between individuals.


- Dr. Vergara, Dr. Kane, and the CGRI Team


Rohlf FJ (2008) tpsDig, digitize landmarks and outlines, version 2.12.
Department of Ecology and Evolution, State University of New York at Stony Brook, © 2005 by F James Rohlf.

Copyright © Cannabis Genomic Research Initiative, 2014.