Melissa Clark / New York Times News Service

The last bottle of holiday wine has been drunk, the discarded Christmas trees have been pulped to mulch and my local farmers market has shrunk to a few crates of muddy roots and yellowing kale. It’s time to celebrate something new: the arrival of blood oranges.

Citrus season is in full swing, with tangerines, pomelos and Meyer lemons at their most fragrant and alluring. But none have the festive flair of the crimson-fleshed blood orange. And with more growers planting the somewhat finicky fruit, they are fast becoming nearly as easy to find as clementines — at least from now until April.

Blood oranges were the result of a spontaneous mutation of the sweet orange. The color develops when the fruit is grown in climates with cold nights and warm, sun-filled afternoons.

In Italy, blood oranges are the most popular kind of table oranges. Order a glass of orange juice in Rome and chances are you’ll be served something ruby-hued. The best blood oranges there are rooted in the rich volcanic soil near Mount Etna in Sicily, though they can also grow in other parts of the Mediterranean. In the United States, most are grown in California’s Central Valley, although Arizona and Texas cultivate the fruit as well. And you occasionally see blood oranges imported from Sicily; they tend to be juicer than their American cousins.

There are three main varieties: Italians swear by the variegated blond and scarlet Tarocco, which has a sweet, berrylike flavor and soft, easy-to-peel skin. Taroccos’ red pigment deepens as they reach maturity, which in Italy happens around Valentine’s Day.

Taroccos do not have a blush on their skins, which makes them a harder sell in the United States, said Celso Paganini, a partner in Porto Pavino, an Italian culinary importing company. Not so the Moro, whose striking, crimson flesh bleeds onto their skin as they mature. In Italy, tart Moros are mostly used for juice. But here in the States, the vibrant color has made them a favorite of chefs and mixologists alike.

Finally there’s the thin-skinned Sanguinello, a full-blood variety (similar to the Moro) that isn’t often seen here.

If you have a choice when you’re shopping, choose the Moro for looks and the Tarocco for flavor. Either way, pick fruit that is heavy for its size, an indicator that it’s full of juice (a good tip for any type of citrus).

You can eat blood oranges out of hand like navels. Or toss them into a simple winter salad dressed with olive oil and flaky salt. Paganini recommends peeling the fruit, then slicing them crosswise — “like salami,” he said — and dressing with a few drops of good balsamic and a shower of chopped fennel fronds. A few slivers of sweet onion won’t hurt, either. Or mix blood and regular oranges for a pretty salad that helps banish the winter blahs.

Recently, I tossed blood orange segments into a salad of roasted carrots, salty olives and freshly ground spices, which was refreshing, satisfying and stunning with its sunset colors.

Because of their acidity, blood oranges are also excellent with fish. I mixed slices with lime and stuffed them into whole fish, seasoned with fennel and garlic.

And although in Italy a blood orange is often served for dessert all by its lonesome, I sugar things up by making them into an upside-down cake spiked with cornmeal. It’s about as festive as a fruit dessert can get, especially in the cold days of a long winter.

Roasted Fish with Blood Orange and Fennel

Makes 4 servings.

2 fennel bulbs

2 limes

4 whole, cleaned black bass or other mild, flaky fish (about 11⁄4 lbs each)

3 TBS plus 4 tsp extra-virgin olive oil, more for drizzling

1 tsp coarse kosher salt, more as needed

Black pepper, as needed

1 blood orange, thinly sliced

2 garlic cloves, thinly sliced

Heat oven to 450 degrees. Line a large, rimmed baking sheet with foil; have ready a second rimmed baking sheet.

Trim the tops from the fennel bulbs and coarsely chop 1⁄4 cup of the fronds; discard the stalks. Remove the outer layers of the fennel and halve each bulb through the root end. Thinly slice each bulb. Thinly slice one of the limes and quarter the other.

Pat each fish dry and coat each lightly with a teaspoon oil. Generously season fish inside and outside with salt and pepper. Transfer fish to the foil-lined baking sheet. Stuff each cavity with slices of lime and orange, fennel fronds and garlic.

Toss sliced fennel with 3 tablespoons oil, 1 teaspoon salt and 1⁄4 teaspoon pepper. Spread on second baking sheet. Transfer fish and fennel to oven; roast fennel, tossing occasionally, until golden and tender, about 15 minutes. Bake fish until it is just opaque, 15 to 20 minutes. Serve fish drizzled with more olive oil and squeeze fresh lime juice on top. Serve with fennel on top or alongside.

Upside-Down Blood Orange Cake

Makes 8 servings.

270 g unsalted butter (2 sticks plus 3 TBS), at room temperature

130 g light brown sugar (about 2⁄3 C)

2 tsp fresh lemon juice

2 med blood oranges

122 g fine cornmeal (about 1 C)

65 g all-purpose flour (about 1⁄2 C)

8 g baking powder (about 11⁄2 tsp)

2 g fine sea salt (about 1⁄2 tsp)

200 g granulated sugar (about 1 C)

4 lg eggs, at room temperature

1⁄3 C sour cream

2 tsp vanilla extract

Heat oven to 350 degrees. Grease a 9-inch round cake pan.

In a small saucepan over medium heat, melt 3 tablespoons (45 grams) butter. Add the brown sugar and lemon juice; stir until sugar melts, about 3 minutes. Scrape mixture into bottom of prepared pan.

Grate 1⁄2 teaspoon zest from one of the oranges, then slice off the tops and bottoms of both oranges. Place oranges on a clean, flat surface, and slice away the rind and pith, top to bottom, following the curve of the fruit. Slice each orange crosswise into 1⁄4-inch-thick wheels; discard any seeds. Arrange orange wheels on top of brown sugar mixture in a single, tight layer.

In a large bowl, whisk together orange zest, cornmeal, flour, baking powder and salt. In a separate bowl, cream together remaining 2 sticks (225 grams) butter with granulated sugar. Beat in eggs, one a time, then beat in sour cream and vanilla. Fold in the dry mixture by hand.

Scrape batter into pan over oranges. Transfer to oven and bake until cake is golden brown and a toothpick inserted in the center emerges clean, 40 to 50 minutes. Cool cake in pan 10 minutes, then run a knife along pan’s edges to loosen it; invert onto a platter and cool completely before serving.

Moroccan Carrot-Blood Orange Salad

Makes 4 servings.

1 lb carrots (about 8 med), peeled and trimmed

1 tsp whole cumin seed

1 tsp whole coriander seed

1 tsp whole fennel seed

1⁄4 C extra-virgin olive oil

1 tsp coarse kosher salt, more to taste

Lg pinch cayenne

4 med blood oranges

2 garlic cloves, minced

2 tsp fresh lemon juice, more to taste

2 C baby arugula

1⁄4 C pitted, oil-cured olives, roughly chopped

Heat oven to 425 degrees.

Quarter the carrots lengthwise and cut each length crosswise into 2-inch chunks. With a mortar and pestle or using the side of a knife, lightly crush the cumin, coriander and fennel. Spread carrots on a large rimmed baking sheet and toss with 2 tablespoons oil, crushed spices, 3⁄4 teaspoon salt and cayenne. Transfer to oven and roast, tossing occasionally, until carrots are tender and caramelized, 30 to 40 minutes. Cool to room temperature.

Meanwhile, grate zest of 1 orange into a small bowl. Whisk in garlic, remaining 1⁄4 teaspoon salt, and lemon juice. Whisk in 2 tablespoons oil.

Slice the tops and bottoms from each orange. Stand each orange on a flat surface and slice away the rind and pith, top to bottom, following curve of the fruit. Hold oranges over a large bowl and slice away fruit between the membranes, releasing segments into the bowl.

Toss carrots, arugula and olives into the bowl. Gently toss in dressing. Taste and add more salt and lemon juice if necessary.