Hemp vs. Marijuana: It’s All Cannabis
By Ted Menadier
Cannabis has become one of the most misunderstood agricultural and legal industries in the United States. Since the passage of the 2018 Farm Bill, confusion surrounding the distinction between hemp and marijuana has increased significantly among consumers, law enforcement, attorneys, and even industry professionals.
The reality is simple: hemp and marijuana are both cannabis. The legal distinction between the two is based almost entirely on THC concentration, not appearance, smell, or plant structure.
This paper provides an overview of the differences between hemp and marijuana under federal law, explains why the two are virtually indistinguishable without laboratory testing, discusses current testing methodologies, and examines the growing market for hemp-derived cannabinoids and THCA products.
I will also address the tendency for cannabis yield and valuation estimates to be significantly overstated in criminal and civil matters.
About the Author
Ted Menadier has worked in the cannabis industry since 2015 in both hemp and marijuana sectors. He serves as a cannabis expert witness and consultant in matters involving cultivation, hemp compliance, cannabis valuation, economic damages, and cannabis-related insurance claims across multiple states.
Ted is a Certified Hemp Sampler for the State of Colorado and a Certified Commercial Cannabis Expert through the Association of Certified Commercial Cannabis Experts.
For additional background and credentials, visit the About Ted Menadier
Definitions
Cannabinoids
Cannabinoids are chemical compounds produced primarily in the resin glands of the female cannabis flower. THC and CBD are the two most widely recognized cannabinoids, though the cannabis plant produces more than 100 known cannabinoids.
Marijuana
Under the 2018 Farm Bill, marijuana is cannabis containing more than 0.3% Delta-9 THC on a dry weight basis.
Hemp
Under the 2018 Farm Bill, hemp is cannabis containing no more than 0.3% Delta-9 THC on a dry weight basis.
CBD
CBD (cannabidiol) is a non-intoxicating cannabinoid commonly found in higher concentrations in hemp varieties.
CBD Isolate
CBD isolate is a refined hemp-derived extract that is typically 99% pure cannabidiol.
THCA
THCA (tetrahydrocannabinolic acid) is the naturally occurring precursor to Delta-9 THC. When heated, THCA converts into Delta-9 THC through a process known as decarboxylation.
This conversion typically occurs between approximately 220°F and 245°F, though conversion rates vary depending on temperature and duration of exposure.
THCA Flower
THCA flower refers to cannabis flower that tests below 0.3% Delta-9 THC but may contain very high levels of THCA, often exceeding 20%.
Although these products may technically qualify as hemp under certain interpretations of the Farm Bill when sold as finished products, they would generally fail pre-harvest hemp compliance testing because total potential THC exceeds legal limits.
Chemically and visually, THCA flower is effectively indistinguishable from marijuana.
Terpenes
Terpenes are aromatic compounds produced by cannabis and many other plants. They contribute to the smell and flavor profile of cannabis.
Volatile Sulfur Compounds
Cannabis also produces volatile sulfur compounds, which contribute to the plant’s characteristic skunk-like odor.
Hemp-Derived Cannabinoids and Conversions
Many intoxicating hemp-derived products sold today are created through chemical conversion processes using CBD isolate extracted from hemp.
These include:
Delta-8 THC
Delta-10 THC
THCP
THCO
Hemp-derived Delta-9 THC
While small quantities of some of these cannabinoids occur naturally in cannabis, commercially viable quantities are typically produced through laboratory conversion processes.
These converted cannabinoids are commonly infused into:
vape products
gummies
concentrates
sprayed hemp flower
The 2018 Farm Bill
The 2018 Farm Bill defines hemp as:
“Cannabis sativa L. and any part of that plant, including the seeds thereof and all derivatives, extracts, cannabinoids, isomers, acids, salts, and salts of isomers, whether growing or not, with a delta-9 tetrahydrocannabinol concentration of not more than 0.3 percent on a dry weight basis.”
Under federal hemp regulations, hemp must be tested prior to harvest to determine total THC concentration.
Pre-harvest compliance testing includes conversion calculations that account for THCA’s potential to become Delta-9 THC after decarboxylation.
This is important because cannabis plants cannot reliably be identified as hemp or marijuana based on appearance or odor alone.
A crop that exceeds legal THC thresholds may require remediation or destruction depending on applicable state and federal regulations. Crops testing above 1% THC may trigger more significant regulatory consequences.
The THCA Loophole
One of the largest gray areas in the hemp industry involves THCA flower.
A product may contain:
less than 0.3% Delta-9 THC
more than 20% THCA
Under certain interpretations of the Farm Bill, that product may still be marketed as hemp because only Delta-9 THC is being measured in the finished product.
However, if the same flower were tested under standard pre-harvest hemp compliance rules using total THC calculations, it would generally exceed legal hemp limits.
This has created a rapidly growing THCA marketplace in which products chemically identical to marijuana are sold as hemp in many jurisdictions.
Hemp and Marijuana Are Visually Indistinguishable
Hemp and marijuana are both cannabis plants. The legal distinction between them is based primarily on THC concentration, not botanical differences.
As a cannabis expert, I cannot conclusively distinguish hemp from marijuana without laboratory testing.
Cannabis varieties can differ widely in:
color
terpene profile
density
trichome production
cultivation method
However, those differences exist across all cannabis varieties, including both hemp and marijuana.
Comparing hemp and marijuana by smell alone would be similar to attempting to identify specific wine grape varieties solely by aroma.
Odor Detection and Drug Dogs
The similarity between hemp and marijuana has also created significant challenges for law enforcement.
The UNC School of Government noted the following regarding narcotics detection dogs:
“Police narcotics K-9s cannot tell the difference between hemp and marijuana because the K-9s are trained to detect THC which is present in both plants.”
If trained detection dogs cannot reliably distinguish hemp from marijuana by odor, it is unreasonable to assume humans can do so consistently without testing.
Appearance and Processing
Cannabis flower can range in color from light green to deep purple and may contain orange, red, or brown pistils.
Harvesting methods, curing, storage conditions, trimming practices, and genetics can all significantly affect appearance and odor.
Additionally, CBD flower is frequently infused or sprayed with converted cannabinoids such as Delta-8 THC or THCP. These products often remain visually indistinguishable from traditional marijuana flower.
Cannabis Testing Methods
The two primary laboratory methods used to test cannabis are:
Gas Chromatography (GC)
High-Performance Liquid Chromatography (HPLC)
The distinction between these testing methods is legally significant.
Gas Chromatography (GC)
Gas chromatography uses heat during testing, which converts THCA into Delta-9 THC.
As a result, GC testing may show significantly higher Delta-9 THC concentrations because decarboxylation occurs during analysis.
High-Performance Liquid Chromatography (HPLC)
HPLC testing does not heat the sample.
Instead, it measures:
THCA separately
Delta-9 THC separately
This distinction is one reason THCA products may test below 0.3% Delta-9 THC while still containing extremely high levels of total potential THC.
To estimate total potential THC, laboratories commonly apply a conversion factor of 0.877 to THCA values.
Hemp-Derived Products
Hemp-derived concentrates, waxes, edibles, and vape products are often chemically indistinguishable from marijuana-derived products.
Many contain:
high THCA concentrations
converted cannabinoids
cannabis-derived terpenes
Without laboratory analysis, it is generally impossible to distinguish hemp-derived products from marijuana-derived products based solely on appearance or smell.
Yield and Valuation Estimates
In my experience, cannabis yield and valuation estimates are frequently overstated, particularly in criminal investigations.
I have reviewed cases in which:
yield estimates were overstated by several multiples
valuation estimates exceeded realistic market values by substantial margins
Accurate valuation requires consideration of:
usable dried flower weight
cultivation method
processing losses
harvest conditions
wholesale versus retail pricing
regional market conditions
Roots, stalks, stems, and fan leaves generally have little to no meaningful market value in traditional cannabis flower markets and should not be included in flower yield calculations.