Streptanthus glandulosus subsp. albidus

'Streptanthus glandulosus'' subsp. albidus is a subspecies of flowering plant in the mustard family known by the common name Metcalf Canyon jewelflower'''. It is endemic to California, where it is known only from the Central Coast Ranges in the San Francisco Bay Area. It grows in open areas such as grasslands, often on serpentine soils.

Description
It is an annual herb producing an erect, usually branching stem up to a meter tall or slightly taller. There are bristly hairs around the base. The basal leaves are lance-shaped with toothed edges and are borne on winged petioles. Leaves farther up the stem are 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 is white or green-tinged. The fruit is a long, narrow silique which may be 12 centimeters in length.

Distribution
It is federally listed as an endangered species of the United States. It is endemic to Santa Clara County, where it is known from nine recent occurrences in the vicinity of Mount Hamilton.

It can be found in isolated and inaccessible mountains on a variety of soils including rock, gravel, and heavy clay.

Threats and conservation efforts
This flora is currently considered endangered according to the U.S. Fish and Wildlife Service. It was added to the United States Forest Service's watch list in 2003. There are a multitude of threats facing these plants. A lot of these animals are threatened by wind turbine facilities and off highway vehicle automotive usage. Cars trucks damage the soil and disturb the ground environment. Another threat that is very common in California are frequent fires and those in the wrong season. There could also be the potential threat from cattle grazing or logging in the near future. As of now there are no specific conservation efforts in place to protect these flowers.