Calyx
Definition: In cannabis growing, the calyx is the small, teardrop-shaped green pod that wraps a female flower's ovule and forms the basic building block of a bud. Botanists would call this structure a bract; the true calyx is a thin film inside it. Calyxes are heavily coated in trichomes and swell as harvest approaches.
How Calyx works
Each cannabis bud is a cluster of many individual female flowers. Every flower consists of an ovule enclosed in a small leafy pod, with two hair-like stigmas, the pistil hairs, sticking out of the tip to catch pollen. Growers call that pod the calyx. Strictly speaking it is a perigonal bract, and the botanical calyx is a nearly invisible membrane hugging the ovary. The grower’s usage is so common that you will see it on spec sheets everywhere.
Why calyxes matter
- Resin: calyxes carry one of the highest densities of glandular trichomes on the plant.
- Maturity: in the final 2 to 3 weeks, calyxes swell noticeably. Fat, tight calyxes are one sign of a ripe bud.
- Seeds: if a flower is pollinated, a seed grows inside its calyx, which then swells and may split.
Calyx-to-leaf ratio
Breeders prize strains with a high calyx-to-leaf ratio, meaning buds made mostly of calyxes with few sugar leaves poking through. These buds trim faster, look cleaner, and put more of the plant’s resin into the part you keep. Low-ratio strains are leafier and take longer to trim, though their trim can still go into hash or edibles.