Descurainia pinnata aka Green Tansymustard

Descurainia pinnata belongs to the mustard family, Brassicaceae. It is an annual, which lives for one year. People call it western tansymustard or Menzies' tansymustard. Its native range spans North America. This includes Canada, the United States, and Mexico. It grows across much of the American Southwest. There, it grows at many heights above sea level. It suits dry ground, bare soil, and disturbed sites. It can form broad patches where these sites suit it.

This plant grows fast, reaching about 3 feet (0.9 metres) tall. It spreads about 1.6 feet (0.5 metres) wide. Its green growth gives open ground a soft texture. The leaves have hairs you can still feel when eating them. Plants For A Future gives June to August as its bloom time. Each flower has both male and female organs. Bees and other insects carry pollen between the flowers. The blooms also draw butterflies. The plant is self-fertile: its own pollen can set seed. Seeds ripen from August to September.

Grow this plant in sun or light shade. It suits sandy soil and loam, even with few nutrients. The soil can be slightly acid, neutral, or slightly alkaline. It grows in dry or moist soil and withstands drought. Plants For A Future lists USDA hardiness zones 4–9. Grow new plants from seed. It can also shed seed and grow freely on open, disturbed ground. This means it may become a weed where sites suit it.

Its main garden uses are in naturalised areas and planting to restore land. It gives cover for a season, not a showy bloom display. Birds and small animals eat its seeds. Its flowers feed insects in dry places. People also eat the leaves and seeds. Cook the leaves as greens, or eat small amounts raw. Raw leaves taste bitter and hot, with a taste like turnip. You can toast seeds and store them for later use. The source lists seedpods as safe to eat, too.

Native Americans have used seed preparations for stomach complaints. Records also note plant poultices for toothache. These are plant packs placed on the body. Other uses include washes for sores. These records do not prove that such uses are safe or help. Reports warn that the plant can poison livestock. The risk is greater when they eat large amounts. Signs include loss of sight and trouble swallowing. Do not gather food from polluted or mineral-rich ground. Dry stems may splinter as you harvest seeds, so wear gloves.