Same species, different legal categories
Hemp and marijuana are not different species. Both are Cannabis sativa L., and cultivars bred for either purpose can be grown the same way, indoors, outdoors or in greenhouses.
The line between them is drawn by law. In general terms, cannabis with a THC concentration at or below a set threshold (historically 0.3 percent delta-9 THC on a dry-weight basis under federal law) is treated as hemp, and cannabis above it is treated as marijuana.
Why THC measurement controls
Because the categories are defined by THC, classification depends on how THC is measured: which compound is counted, whether THCA is included, how the sample was taken and when.
A plant can move across the line as it matures. Harvest timing, sampling method and the calculation used can each change the result.
- Delta-9 THC alone versus total THC including THCA
- Pre-harvest field sampling versus testing of finished product
- Dry-weight basis and moisture
- Which portion of the plant was sampled
Why appearance and smell are unreliable
Hemp flower grown for cannabinoids can look identical to marijuana flower. Leaves, buds and trichomes do not reveal THC concentration.
Aroma comes largely from terpenes, which both produce. A person cannot smell THC. This is why odor and visual identification are frequently contested after hemp became widely lawful.
Where hemp vs marijuana questions arise in litigation
Classification is central in seizures of hemp shipments, prosecutions involving hemp or THCA flower, crops that test above the limit, and contract disputes where a buyer rejects product on testing grounds.
A note on changing law
Hemp and marijuana definitions have been amended over time at the federal level and differ by state. Which definition applies depends on the date, the jurisdiction and the product, and is a question for counsel.
Need this analyzed in a matter?
Ted Menadier, MBA provides expert witness services in litigation involving cannabis, marijuana and hemp cultivation, crop loss, crop valuation, business operations, insurance claims, testing, classification and related industry matters. Request a consultation or see information for attorneys.