Trichome

Trichome

Trichomes on a plant bud

Trichomes are fine outgrowths or appendages on plants, algae, lichens, and certain protists. They are highly variable in form and function and can be found on the stems, leaves, flowers, and fruits of plants. Trichomes can be unicellular or multicellular and may be glandular or non-glandular.

Types of Trichomes

Trichomes can be classified into several types based on their structure and function:

Non-Glandular Trichomes

Non-glandular trichomes are primarily involved in protecting the plant from herbivores and environmental stress. They can be simple hairs or more complex structures.

Glandular Trichomes

Glandular trichomes on Drosera capensis

Glandular trichomes secrete substances such as oils, resins, or mucilage. These secretions can deter herbivores, attract pollinators, or reduce water loss. For example, the glandular trichomes on the leaves of the carnivorous plant Drosera capensis secrete a sticky substance to trap insects.

Functions of Trichomes

Trichomes serve various functions depending on their type and location:

• Protection: Trichomes can protect plants from herbivores by making the plant surface less palatable or more difficult to consume.
• Temperature Regulation: They can help in regulating temperature by reflecting sunlight and reducing water loss through transpiration.
• Secretion: Glandular trichomes can secrete substances that deter herbivores or attract pollinators.
• Physical Barrier: They can act as a physical barrier against pathogens and insects.

Trichomes in Different Plants

Close-up of cannabis trichomes

Trichomes are found in a wide variety of plants, each adapted to the specific needs of the plant:

• Cannabis: The trichomes on cannabis plants are known for producing cannabinoids, which have psychoactive and medicinal properties.
• Solanum scabrum: This plant has trichomes on its leaf lamina that can deter herbivores.
• Solanum quitoense: The petiole of this plant is covered with trichomes that may protect it from pests.

Fossilized Trichomes

Trichomes preserved in amber

Trichomes can also be found in the fossil record, preserved in substances like amber. These fossilized trichomes provide valuable information about ancient plant life and the environments in which they lived.

Related Pages

• Plant morphology
• Glandular hair
• Leaf
• Plant defense against herbivory