Sessility (botany) subsessile, which is not completely sessile. Sessility (botany) In botany, sessility (meaning "sitting", used in the sense of "resting on the surface") is a characteristic of plant parts that have no stalk. Flowers or leaves are borne directly from the stem or peduncle, and thus lack a petiole or pedicel. The leaves of most monocotyledons lack petioles. The term sessility is also used in mycology to describe a fungal fruit body that is attached to or seated directly on the surface of the substrate, lacking a supporting stipe or pedicel. Other examples of sessile flowers include Achyranthus, Saffron, etc. Plant
Calyx of Held principal neuron with a distinct morphology: branching of the calyx allows the creation of second- and third-order networks. Each branch establishes a connection with the principal neuron, establishing a large number of active zones. This is unusual for synaptic terminals in the brain, as most create a single active zone. Each calyx contains anywhere from 300 to 700 active zones, and in each of the active zones there are about 100 glutamate-containing vesicles with about 3 docked vesicles at a time. These vesicles are large, consistent with the findings regarding quantal size in other adult synapses. Dense-core vesicles, usually containing