Cucurbita maxima.

The original — the matriarch of all North American buttercup squashes. Selected in the 1920s by the horticulturist Albert Yeager at the North Dakota Agricultural Experiment Station, then popularized starting in 1932 by the Burgess Seed Company of Illinois, it was for a long time the uncontested standard of its category, and remains, nearly a century later, one of the winter squashes most loved by cooks. Its French name renoncule ("buttercup") comes from its silhouette — a flattened drum topped by a small round cap on the blossom end, evoking the bud of that wildflower.

Dark green skin striped with paler green, a compact fruit of 1.5 to 2.5 kg — just the right size for two to four family meals. But it's on the plate that it truly stands out: bright orange flesh, dense, dry, fibreless, of an almost confectionery sweetness, often compared to sweet potato but with a more earthy, more nutty note. Roasted in quarters with butter and maple syrup, puréed for gnocchi, as a filling for ravioli, in a velouté with cream and nutmeg, or as a replacement for pumpkin in a pie (where it is frankly superior).

Good keeper for 3 to 4 months in a cool, dry place, after a one- to two-week skin-curing period in the sun.

Grower's tip: 100 days is long for Québec. Start indoors 3 to 4 weeks before transplanting (no more — cucurbits hate long stays in a pot; their roots coil and the plant suffers lastingly). Transplant once the soil is well warmed and all risk of frost is past. For the squash to ripen in time, leave only 2 to 3 fruits per plant by pinching off the extra flowers in August — concentrating the sap in fewer fruits speeds maturation and improves quality. Harvest before the first serious frost, keeping 5 cm of stem for good storage life.

• Open-pollinated. Monoecious (separate male and female flowers on the same plant), bee-pollinated; crosses with other Cucurbita maxima (giant pumpkins, hubbards, kabocha) — isolate for seed saving.
• Vine length: 3 to 4 m. Plan the space, or train on a sturdy trellis with support for the fruits.
• Maturity: about 100 days after transplant.
• Exposure: full sun.
• Rich, deep soil, heavy with organic matter. Space plants 1.5 m apart in all directions.
• Start indoors 3 to 4 weeks before last frost, or direct-sow in a mound in early June once the soil is well warmed (18 °C minimum).