Trichome
Definition: Trichomes are tiny hair-like and mushroom-shaped growths on cannabis flowers, sugar leaves and stems. The glandular types produce and store resin rich in cannabinoids such as THCA and CBDA, along with aromatic terpenes. Trichomes give buds their frosty look, and their color shift from clear to cloudy to amber helps growers time the harvest.
How Trichome works
The plant likely evolved resin glands as protection. Sticky, bitter, aromatic resin deters insects and grazing animals and may shield tissue from UV light and drying winds. For growers, trichomes are where almost all of the value sits.
Three main glandular types
- Bulbous: the smallest, scattered over the whole plant surface and nearly invisible without a microscope.
- Capitate-sessile: small round heads sitting almost flat on the surface.
- Capitate-stalked: the classic mushroom shape, with a stalk and a round gland head. Most abundant on calyxes during flowering and the richest source of cannabinoids and terpenes.
There are also non-glandular trichomes, simple pointed hairs that produce no resin.
Trichomes and harvest timing
Under a 60x loupe, gland heads change as the plant ripens: clear at first, then milky or cloudy as cannabinoid levels peak, then amber as some THC oxidizes into CBN. Reading this shift is the most reliable way to find your harvest window.
Protecting them
Trichome heads are fragile. Rough handling, warm drying rooms and grinding knock them off or evaporate their terpenes. Collected trichomes are what growers sift into kief and press into hash.