# Bulbous trichome

> The smallest glandular trichome on cannabis, a few cells with a tiny head (about 10-30 µm), scattered over leaves and stems.

- Canonical: https://genetixbay.com/knowledge/glossary/bulbous-trichome.html
- Also written: bulbous trichomes, bulbous gland, bulbous glandular trichome
- Glossary category: Plant biology · Evidence: Established
- Status: Draft: awaiting expert review · Updated: 2026-10-31
- Licence: CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/), attribute "GenetixBay cannabis glossary"

A bulbous trichome is a minute glandular [trichome](https://genetixbay.com/knowledge/glossary/trichome.md) made of a few cells: a one- or two-celled base and a small secretory head, often only 10-30 µm across. They occur widely on leaves, stems and [bracts](https://genetixbay.com/knowledge/glossary/bract.md) of cannabis plants of both sexes. Their contribution to total resin is small because each holds so little.

## In practice

Most growers never notice bulbous trichomes; even with a 60x [loupe](https://genetixbay.com/knowledge/glossary/jewelers-loupe.md) they appear as faint specks among larger glands. They are mainly of interest in botanical descriptions, in microscopy of trichome development, and when explaining why some resin is found even on leaves that carry few visible glands.

When people grade frost or count glands for harvest, they are looking at [capitate-stalked](https://genetixbay.com/knowledge/glossary/capitate-stalked-trichome.md) heads, not bulbous ones.

The three-way classification (bulbous, [capitate-sessile](https://genetixbay.com/knowledge/glossary/capitate-sessile-trichome.md), capitate-stalked) comes from classic microscopy of cannabis epidermis and is still used in current research.

## Don't confuse with

- **Capitate-sessile trichome**: larger head, sits on the surface without a tall stalk.
- **Capitate-stalked trichome**: the big mushroom gland on bracts.
- **Cystolith trichome**: non-glandular hair with a calcium carbonate crystal.

## Related terms

[Trichome](https://genetixbay.com/knowledge/glossary/trichome.md), [Capitate-sessile trichome](https://genetixbay.com/knowledge/glossary/capitate-sessile-trichome.md), [Capitate-stalked trichome](https://genetixbay.com/knowledge/glossary/capitate-stalked-trichome.md)

## Read more

- [Cannabis plant biology: the parts and what they do](https://genetixbay.com/knowledge/basics/cannabis-plant-biology.md)

## Sources

1. Livingston SJ, Quilichini TD, Booth JK, et al. 2020. Cannabis glandular trichomes alter morphology and metabolite content during flower maturation. The Plant Journal 101(1):37-56. https://doi.org/10.1111/tpj.14516
2. Small E. 2015. Evolution and classification of Cannabis sativa (marijuana, hemp) in relation to human utilization. The Botanical Review 81:189-294. https://doi.org/10.1007/s12229-015-9157-3