Pods break apart transversely into segments. No information available. Dry disturbed sites, winter annual crops, especially winter wheat, roadsides, waste places. Tolerates a broad range of moisture, temperature, and soil conditions. Cascade Ranges, Central Valley, South Coast Ranges, South Coast, Great Basin.
Germination occurs during the cool season, mostly after the first rains.
Seedlings exist as basal rosettes until flowering stems are produced in early spring. Viable seed can be produced in as few as 10 days after flowers open. Infestations can be difficult to control in grainfields because plants are somewhat tolerant to typical 2,4-D use rates. Rotation to spring planted crops produces additional control options, including cultivation or other registered herbicides. Malcolm stock occurs in dry disturbed areas and desert shrublands from the eastern Sierra Nevada to the Rocky Mountains.