Streptanthus albidus smaller and narrower, sometimes linear in shape, and toothed or smooth-edged. Flowers occur at intervals along the upper stem. Each has a spherical to urn-shaped calyx of keeled sepals about a centimeter long with curving petals emerging from the tip. The calyx of sepals may be white to purple, depending on subspecies. The fruit is a long, narrow silique which may be 12 centimeters in length. There are two subspecies, both rare. Streptanthus albidus Streptanthus albidus is a species of flowering plant in the mustard family known by the common name Metcalf Canyon jewelflower. It is endemic to California, where
Calyx of Held a mature calyx that facilitates the consistent, rapid spread of signals in the MNTB-VCN area. A select few processes occur during early neuronal development in order to ensure proper calyx formation, specifically through the influence of Fibroblastic Growth Factor (FGF), transcription factor Math5, neural cell recognition molecule NB-2, and ephrin (Eph) proteins in cells. Math1/Math5 and FGF are two regulators essential for appropriate growth and development of the cochlear nucleus complex, which comprises both the ventral cochlear nucleus (VCN) and the dorsal cochlear nucleus (DCN). Sufficient FGF levels ensure proper morphology of the cochlear nuclei, while Math5 insures correct size