Rosette (botany) Rosette (botany) In botany, a rosette is a circular arrangement of leaves or of structures resembling leaves. In flowering plants, rosettes usually sit near the soil, their structure is an example of a modified stem in which the internode gaps between the leaves do not expand, so that all the leaves remain clustered tightly together and at a similar height. In bryophytes and algae, a rosette results from the repeated branching of the thallus as the plant grows, resulting in a circular outline. Many plant families have varieties with rosette morphology; they are particularly common in Asteraceae (such as dandelions),
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.