Streptanthus barbatus bristly edges (no more than 3 centimeters long) and borne on short petioles. Leaves above these are oval to rounded and may clasp the stem. Flowers occur at intervals along the upper stem. Each has a spherical to urn-shaped calyx of keeled sepals under a centimeter long with curving petals barely emerging from the tip. The calyx of sepals is whitish, darkening purple in maturity. The petals are purple. The fruit is a long, flat, curving silique which may be 7 centimeters in length. Streptanthus barbatus Streptanthus barbatus is a species of flowering plant in the mustard family known by
Calyx of Held The first is that in the second week of development, myelination of the VCN axons in the MNTB increases. This prominent growth in myelin corresponds to the chronological development of the signaling circuit and adaptation of the calyx. The second ultrastructural change involves the principal neurons of the MNTBs, whose cell bodies and nuclei increase in surface area due to enlargement. This is a direct result of individual, larger postsynaptic densities breaking up into smaller, multiple densities. Potassium channels are vital in conducting the presynaptic action potential. The calyx contains several types of potassium channels, each differing in location and