Lactuca sativa.

A venerable French lettuce, already grown in the kitchen gardens of the Ancien Régime and listed in the Vilmorin company catalogs from the 18th century onward. It takes its name from the elegantly cut silhouette of its leaves — a lobed profile recalling, in miniature, the large oak leaves edging a sugar bush. It's probably the prettiest lettuce you can plant in a vegetable garden: each rosette forms an open corolla that looks more like a green (or red, depending on the selection) flower than a vegetable.

A loose-leaf type — no head forms; you pick leaf by leaf at the periphery, or take the whole rosette with a knife. A delicate, almost silky texture, halfway between butter lettuce and the curly types — not the brittle crunch of romaine or iceberg, but a tenderness that makes it the perfect setting for elegant composed salads with warm goat cheese, grilled lardons, hazelnuts, raspberries or poached pear. Mild, sweet flavour, with the faintest nutty note in the finish. A precious quirk: it's one of the most heat-tolerant lettuces, resisting bolting longer than most other varieties — hence its historical popularity in the warmer French kitchen gardens.

Grower's tip: Like all lettuces, it germinates poorly above 25 °C. For summer sowings, pre-soak the seeds overnight in the fridge, or start them in cells indoors in a cool spot. Oak Leaf lends itself particularly well to mesclun — sown densely in tight rows and cut young with scissors at 8-10 cm tall, it regrows two or three times from the base before exhausting itself; a single row can feed you in salad for a month and a half. Harvest in the early morning, when the leaves are full of overnight freshness.

• Open-pollinated. Self-pollinating, so very few crosses to fear — ideal for seed saving.
• Height: 20-25 cm.
• Maturity: 45-55 days for full rosette; young leaves from 25-30 days.
• Exposure: full sun in spring and fall; part shade accepted in summer.
• Rich, cool, well-drained soil. Thin to 20-25 cm for full rosettes, or sow densely for young-leaf cutting.
• Direct-sow as soon as the soil can be worked (mid-April in Québec), in successive rows every two weeks. More heat-tolerant than most lettuces, it can be sown until mid-July without too much risk of bolting.