As with fashion and interior design, trends in book cover art come and go, sometimes inexplicably. One day you’re puzzling over how an exploding rose ended up on multiple dust jackets, and the next you’re confronted by an onslaught of twee illustrations.

These days, book covers are all about nature; they’re festooned with flowers, swirling with birds and littered with leaves. Those aren’t the only trends we’ve noticed, however. Here’s a look at eight, with a couple of samples from each category.

A border of busy botanicals

When it comes to recent books, nothing frames a title quite like a claustrophobic wreath of leaves and flowers.

Charming illustrations of stylized people

These types of figures, particularly popular in the contemporary romance genre, are often set against a teal, magenta or yellow backdrop.

A single bird

Taking a cue from “Portlandia,” a lot of publishers are putting a bird on it. While plenty of covers sport entire flocks, the trend of the avian loner feels especially conspicuous.

A single tree

Those birds need a place to nest, after all.

Color field-inspired abstractions

At first blush, the art on these covers is just sweeps of bright hues, but look more closely and reality comes into focus.

Women walking away

While especially prevalent in historical fiction, this look has caught on in other genres, too. In fact, the imagery is so common, you could break it up into subcategories, like “just the legs” and “woman holding hands with child.”

Defaced faces

Women on covers aren't always retreating. Sometimes they're staring right back at us, giving us time to ponder why they look so . . . wrong.

Stacked silhouettes

You'll find plenty of variations on this striking theme — like the pregnant bellies on Joanne Ramos's “The Farm” and the mountainous vista of “Betty,” by Tiffany McDaniel.