A capitate-sessile trichome is a glandular trichome whose secretory head sits almost directly on the epidermis, with a very short stalk or none visible. Heads are smaller than stalked glands, roughly 25-70 µm across. They occur on leaves, sugar leaves, stems and early-developing bracts.
Livingston et al. (2020) found that, on cannabis flowers, many sessile-looking glands are an early developmental stage of capitate-stalked glands, and that the two differ in metabolism: stalked glands make relatively more monoterpenes and fluoresce differently. Sessile glands on leaves stay sessile.
In practice
On a loupe they look like tiny beads stuck to the leaf surface. Their presence on sugar leaves is why trim from close to the bud carries resin and gets kept for processing, while large fan leaves carry far less.
They matter less for harvest timing than stalked glands, because the flower's bulk resin sits in stalked heads.
Don't confuse with
- Capitate-stalked trichome: tall stalk, large head, dominant on bracts.
- Bulbous trichome: much smaller, a few cells.
- Cystolith hair: non-glandular, no resin.
A hair-like outgrowth of the plant's skin; in cannabis the glandular types make and store the resin holding cannabinoids and terpenes.A small leaf growing from within the flower cluster, often coated in trichomes, which is trimmed off and commonly kept for processing.In cannabis, the small leaf-like sheath (perigonal bract) that wraps each female flower's ovary and carries the densest capitate-stalked trichomes.The large mushroom-shaped glandular trichome on cannabis bracts, with a multicellular stalk and a resin-filled head; it holds most of the flower's cannabinoids and terpenes.A monoterpene is a ten-carbon terpene made from geranyl pyrophosphate, such as myrcene, limonene, pinene or terpinolene; they are the most volatile terpenes and the first lost in drying.A large palmate cannabis leaf with several long leaflets on a long petiole; fan leaves do most of the plant's photosynthesis and carry few trichomes.The span of days, often one to two weeks, in which a cannabis plant is ripe enough to cut, judged mainly by trichome head colour and bud development.The smallest glandular trichome on cannabis, a few cells with a tiny head (about 10-30 µm), scattered over leaves and stems.
