Nasturtium

Tropaeolum majus

Tropaeolaceae

Peppery lily-pad leaves and a spurred flower — a salad plant whose pickled seeds stand in for capers.

Culinary flower, leaf, and pickled seed. Not watercress (Nasturtium officinale), a different plant that stole the name.

Parts used: Leaf · Flower · Green seed
Traditional notes: Salad · Pickled seed · Traditional winter cress folklore
Grow · USDA 6b: Tender annual. Frost kills it. Direct-sow after frost, or start indoors. Soak seed overnight. In work: May · Jun · Jul · Aug · Sep
Harvest: Leaves anytime; flowers as they open; green seeds for pickle.

Poor soil, more flowers. Compost makes a vine of leaves.
Aphids: a rinse, or plant extra.
Climbing types want a fence; dwarfs stay in a pot.

Safety

Mustard-family caution if you react to cress

Companions

Plant with Anise hyssop, Apple, Artichoke, Bee balm, Borage, Broccoli.

Lore

Linnaeus named it Tropaeolum from tropaeum, a trophy — the round leaves and flowers looked to him like shields and helmets on a battlefield pole. Victorian salads were not complete without it. The pickled seeds fooled no one as capers, and fooled everyone as a good idea.

The Herbarium — a teaching catalog, not a clinic. Traditional use is history, not a prescription. USDA 6b dates are a week either way, not a promise. Do not eat, drink, or harvest a plant you cannot name.