Medical Research

Can High CBD Cultivars Be Identified By Appearances Alone?

Written by Colby McCoy

It is a well-known fact that leaf width and length can be used to identify if a cultivar is sativa or indica dominant. Outside of that, common wisdom assumes that looks can be deceiving when trying to ascertain specific qualities of cannabis cultivars. But are they?

A groundbreaking February 2021 study by the American Society for Horticultural Science has discovered that various morphological qualities are highly correlated with high Cannabidiol (CBD) and Tetrahydrocannabinol (THC) cultivars. In the study, morphological traits were monitored in 21 unique cultivars through three stages: vegetative, flowering, harvest and inflorescence.

The study found a positive correlation between high THC and leaf width/length ratio in the 21 cultivars, while high CBD levels were positively correlated with the number of serrations on the central leaflet, the number of leaflets and average length of the central leaflet from each node [1].

“The traits that were positively correlated with THC were all negatively correlated with CBD, where the absolute values of the correlations were similar, and vice versa,” according to the study [1]. So, what does this all mean?

Researchers have another tool to possibly identify CBD/THC concentrations in cultivars prior to any in-depth lab analysis. It is unclear how this will aid the average consumer, however.



  1. Jin, Dan, Philippe Henry, Jacqueline Shan, and Jie Chen. “Identification of Phenotypic Characteristics in Three Chemotype Categories in the Genus Cannabis”. HortScience horts 56.4 (2021): 481-490. <>. Web. 13 May. 2021.

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About the author

Colby McCoy

Colby McCoy is a recent graduate of the University of Georgia who has written for non-profits, marketing firms, and personal blogs. When not writing he can be found trekking the mountain ranges around Seattle, WA, with his two pups Harry and Riley.