The vegetable oyster (Mertensia maritima) is a perennial and creeping herbaceous plant of the Boraginaceae family.
It is a creeping plant, usually glabrous and glaucous green, often forming cushions. Its strongly branched stems are up to 60 cm long and bear slightly fleshy leaves 0.5 to 6 cm long. They are spatulate, obovate or lanceolate, obtuse or apiculate, the lower petiolate, the upper sessile; the blade is glabrous and entire and is punctuated by salt glands above.
The plant bears, in branching terminal cymes, flowers with leafy bracts and cylindrical corollas with pink or white campanulate flowers that turn blue when fertilized. Their pedicels are 2 to 10 mm long and curl when the fruit ripens, a flattened fleshy nut 6 mm in diameter.
The leaves of this plant have an amazing oyster flavor and were eaten as vegetables by various Indian tribes in North America. Its rhizomes are said to have been eaten by the Inuit of Alaska, where this species is also native. The leaves can be used as an accompaniment to fish dishes. Eaten raw, cooked, they can be preserved in vinegar such as sea fennel or samphire. Its taste fades after consuming a few leaves, so it lends itself more to decoration (verrines or toast) than to the composition of salads. It can be obtained from nurseries or fishmongers.
This plant can be harvested from spring to fall. Harvesting in the morning is recommended in order to keep the aromas as much as possible.