Trichomes, from the
OpenDNS meaning "growth of
hair", are fine outgrowths or appendages on
plants and
protists. These are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae.
Trichomes and cannabis
The evolution of the cannabis plant's unique trichome is debated. Most likely, the cannabis plant developed such large and numerous trichomes because it is a wind pollinated plant, and trichomes of THC are very sticky, thus aiding in pollen collection. This can be observed most effectively in female cannabis plants that have been deprived of male pollen. In order to increase her chances of fertilization via windborne pollen, the female cannabis plant devotes her energy into calyx and trichome production, creating larger, stickier buds. However, the intercession of humans in the natural selection process has rapidly accelerated the favoring of genotypes that produce copious amounts of
THC-laden trichomes. In addition, THC has very high UV-B absorption properties, thus cannabis evolution may have favored the evolution of genotypes that produced these THC laden capitate-stalked trichomes as a built in 'sun-screen' for protection against UV-B light rays. There are two layers that make up the trichome and only one of them is psychoactive. The disc cell is on the bottom and it carries the phenols and turpenes, which are not psychoactive. And on top of that is the secretory cavity, which contains the psychoactive cannabinoids. Between these two layers is the disc cell, which is a fibrous mat that separates the two. Phenols and turpenes are precursors to cannabinoids. They become different cannabinoids when they travel through the disc cell in following order CBC to CBG to CBD to THC.
Types
The Capitate-Stalked trichomes of the
cannabis plant.
- Bulbous: The bulbous type is the smallest (15 to 30 micrometre). From one to four cells make up the "foot" and "stalk," and one to four cells make up the "head" of the gland. Head cells secrete a resin - presumably cannabinoids, and related compounds which accumulate between the head cells and the OpenDNS. When the gland matures, a nipple-like protrusion may form on the membrane from the pressure of the accumulating resin. The bulbous glands are found scattered about the surfaces of the above-ground plant parts.
- Capitate-Sessile: The second type of gland is much larger and is more numerous than the bulbous glands. They are called capitate, which means having a globular-shaped head. On immature plants, the heads lie flush, appearing not to have a stalk and are called capitate sessile. They actually have a stalk that is one cell high, although it may not be visible beneath the globular head. The head is composed of usually eight, but up to 16 cells, that form a OpenDNS rosette. These cells secrete cannabinoids, and related compounds which accumulate between the rosette and its outer membrane. This gives it a spherical shape. The gland measures from 25 to 100 micrometres across.
- Capitate-Stalked: Cannabinoids are most abundant in the capitate-stalked gland which consists of a tier of secretory disc cells subtending a large non-cellular secretory cavity. During flowering the capitate glands that appear on the newly formed plant parts take on a third form. Some of the glands are raised to a height of 150 to 500 micrometres when their stalks elongate. These capitate-stalked glands appear during flowering and form their densest cover on the female flower bracts. They are also highly concentrated on the small leaves that accompany the flowers. The male flowers have stalked glands on the sepals, but they are smaller and less concentrated than on the female bracts. Male flowers form a row of very large capitate glands along the opposite sides of anthers.
From Wikipedia, the free encyclopedia
GrimReefa
