Alternate name: Rydberg's Twinpod, Sharp-leaf Twinpod
Family: Brassicaceae, Mustard view all from this family
Description A dwarf, silvery plant bearing dense racemes of yellow flowers.
Habit: native perennial herb; prostrate to erect stems with upturned tips, rising from a basal rosette; woody base; sometimes clump-forming.
Height: 1.5-8 in (4-20 cm)
Leaf: at base, obovate to round, stalked, rarely toothed, 0.7-4 in (17-95 mm) long, 0.25-1.8 in (6-45 mm) wide; on stem, alternate, spatulate to lanceolate, reduced, smaller.
Flower: bright yellow, 0.3-0.5 in (7-12 mm) tall; 4 oval petals; held in small terminal spikes.
Fruit: papery-like pod, green turning purple, with 2 pronounced oval lobes, each 1/4-1/2 in (6-12 mm) long, 1/8-1/4 in (3-6 mm) wide; lobes notched equally above and below, with linear partition.
Flower February to August.
Habitat Dry, open sites in rocky or gravelly soils: arid shrublands, aspen forests, coniferous forests, alpine tundra, hillsides, roadcuts, and sagebrush, pinyon-juniper, Gambel oak, and ponderosa pine communities; 5000-11,500 ft (1500-3500 m).
Range Western U.S.: from Idaho and Montana south to Nevada and New Mexico; mostly within drainage of Colorado River.
Discussion Also known as sharpleaf twinpod, Rydberg's twinpod, pointleaf twinpod. Two varieties are recognized.
Physaria derives from the Greek physa, meaning "bellows," referring to the swollen pod halves. The common name double bladderpod as well as twinpod can be used for any of the 14 species found in the West, most occuring in dry mountain areas.