Buglossoides arvensis aka Corn Gromwell

Buglossoides arvensis belongs to the borage family, Boraginaceae. Gardeners know it as corn gromwell or field gromwell. Other names include pigeon weed and wheat-thief. The RHS also lists the older name Lithospermum arvense. Its native range spans Macaronesia, North Africa, and the Arabian Peninsula. It also extends across temperate Eurasia. The RHS confirms that it is native to Britain and Ireland. Kew places it within the temperate climate zone.

This plant grows as an annual, though Kew also records biennial plants. Plants for a Future gives its height as 1.6 feet [0.5 metres]. It gives the same figure for its spread. Its habitats include crop fields, rough ground, and open grassland. These records place it in open ground and farmed landscapes. Plants for a Future lists meadows and cultivated beds as garden settings. Its reported weed potential deserves attention when choosing a site.

Flowers appear from May to July, according to Plants for a Future. Each flower has both male and female organs. Bees and flies pollinate them. Seeds ripen from July to August, following the flowering period. These dates give a guide to its seasonal cycle. For propagation, sow seed directly where plants will grow in spring. Plants for a Future says germination should take a few weeks.

Choose soil that drains well and has moderate fertility. This species can grow in sand, loam, or clay. It accepts mildly acid, neutral, and mildly alkaline soil. Full sun and partial shade both suit it. Plants for a Future states that it prefers moist soil. Its listed USDA hardiness range is zones 6–10. The same source gives UK zone 7. That label is not an RHS H-scale hardiness rating.

The main food use reported here concerns refined seed oil. The European Union has granted that oil novel food status. Some farmers grow the plant for this purpose. This does not establish that raw seeds or leaves are edible. Plants for a Future gives it a low food-use rating. It also records leaf infusions as a traditional diuretic. That use does not establish safety or medical benefit. The source lists no known hazards, but provides no specific pet-safety evidence. It records no other uses.