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 embryonic calyx formation. One characteristic that distinguishes Eph proteins and their receptors from other signaling systems is their ability to transmit information bidirectionally. Forward and reverse signaling in VCN and MNTB cells is essential for the proper number and formation of VCN and ipsilateral MNTB projections in the calyx. Eph proteins also ensure that while axons pass through the ipsilateral MNTB, branching and final termination of these projections only occur in the contralateral MNTB, possibly because the proteins are only targeted towards specific regions on the axons. Overall, there are two ultrastructural changes that occur in the calyx of Held.