Matricaria occidentalis, commonly known as valley mayweed, is an annual plant native to North America. It is in the family Asteraceae.
The stem is either branching or below the corymbose summit. It is 15cm-45cmcm (06inches-18inchescm) high; not strongly scented; heads as much as 1.5cm (00.6inches) in diameter, conical in shape and greenish yellow in color; achenes are sharply angled. It is used as substitute for chamomile. It is extremely similar to pineapple weed.
Usually occurs in wetlands, but occasionally found in non wetlands. It is native to California and Oregon.[1]