Lomatium macrocarpum aka Bigseed Biscuitroot

Lomatium macrocarpum is a perennial in the carrot family, Apiaceae. Its common names include bigseed biscuitroot and bigseed lomatium. It comes from western and central North America. Its range spans western and central Canada and much of the western United States. It grows on open, rocky hills and plains. Its range does not reach far into the mountains. Kew places it in the temperate climate zone.

The plant grows to about 1.6 feet (0.5 metres) tall. It forms a clump with little outward spread. Plants vary in form, according to Plants For A Future. Each flower has both male and female organs. Insects pollinate the flowers, and the plant can also set seed through self-fertilisation. The supplied sources give no flower colour or bloom season. They also give no detailed account of its leaves or fruit.

Plants For A Future suggests a sunny site with good drainage. It reports that the plant cannot grow in shade. Sandy, loamy and clay soils fall within its stated range. Soil may be mildly acid, neutral or mildly alkaline. It accepts dry or moist ground. The source lists USDA zones 5–10, but notes scant growing data. It does not confirm hardiness in Britain. Cultivated beds are a listed garden setting.

The roots and seeds have recorded food uses. Several Indigenous North American peoples used the roots as a staple. People ate them raw or cooked, often after peeling. Dried roots could be ground into flour for cakes. Seeds could also be eaten raw or cooked. Ground seeds went into bread and cakes, or flavoured soups. Leaves, stems and flowers supplied material for tea. Plants For A Future lists no known hazards. This does not establish safety for pets or every use.

Recorded traditional uses include root preparations for colds and sore throats. Other uses involved weakness, swelling and attempts to aid conception. These records do not establish medical benefit. Dried roots also served as ceremonial incense. For propagation, the source favours sowing fresh seed when ripe. Stored seed may take at least a year to sprout. A cold treatment may shorten that wait. Spring or autumn division may be possible, but remains uncertain. The source does not flag weed potential. The supplied evidence gives no pest or disease details.