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
Discodermia calyx species, among others with similar toxins, became increasingly studied and important in medicine, particularly relating to chemotherapy. In a later study, scientist concluded that the calyculin A, from "D. calyx," also blocks calcium influx by blocking non-selective ion channels in the cell. Later research looked into "D. calyx" as a species to look at the natural mechanisms that can be used to regulate the toxicity of calyculin A. Scientist found regulation through phosphorylation and dephosphorylation. These among other studies focus on regulation of the toxin as a characteristic of the sponge Discodermia Calyx because of its implications in the fight