From its very opening, Anita Amirrezvani’s debut novel “The Blood of Flowers” (Little, Brown; 368 pages; $23.99) indulges in a storyteller’s penchant for aphorism. “First there was and then there wasn’t. Before God no one was,” Ms. Amirrezvani begins, adopting this traditional Iranian introduction (the Persian equivalent of “Once upon a time”) to launch what is, in essence, a fable cloaked in a modern temperament.

“The Blood of Flowers” takes place in the 1620s, in the Persian Empire of Shah Abbas. At the story’s center is an unnamed narrator, a girl of 14 who arrives with her mother in Isfahan, the empire’s capital, after her father’s sudden death. Taken in by her father’s half-brother, a wealthy carpetmaker in the employ of the Shah, the girl becomes fascinated by his craft. Her position in her relatives’ house is an unstable one, however, as her vindictive aunt relegates her and her mother to the role of servants.

The narrator fixates on learning the finer points of carpet design in the hope that she might weave a carpet impressive enough to supplement her dowry and allow her to marry into a new family. Just as the delicate art of carpet-knotting becomes the focal point of the girl’s brash scheme, it proves equally critical to Ms. Amirrezvani’s own narrative. Persian rugs come to life more than any of the characters in the novel — the blossoms and arabesques of their patterns “like watching nature at work, feeding and renewing her own beauty.” The background, more than the narrator or her supporting cast, is the star of “The Blood of Flowers.” The marketplaces of Isfahan — the aromas of lamb roasting on spits and the shouts of clamoring merchants — are a convincing setting for the adventures of the nameless heroine.

Given our particular historical moment, Ms. Amirrezvani is appropriately anthropological in her scope. From the picheh that conceals the narrator’s face in public to the bathing rituals of the hammam, the practices that order the lives of her characters lend the novel a degree of texture that the characters themselves never quite share. Were Ms. Amirrezvani to expend as much attention on the moral reverberations of her plot as she does on Persian culture and customs, the protagonist’s impetuosity might serve as a more coherent comment of the social mores of her place and time. As it stands, Ms. Amirrezvani’s depth of characterization does not match her eye for detail.

The novelist’s descriptive flourishes often gloss over the fact that “The Blood of Flowers” hinges on a plot fraught with moral ambiguity. The story turns on the sigheh, a form of temporary, contractual marriage that, in Persia, appears to be essentially a legally sanctioned form of prostitution: For a fee, a man may take an expendable wife for a duration of his own choosing (no small matter in a society where virginity is a precious commodity). When a rich horse merchant proposes a sigheh to the narrator, it is hardly an attractive offer. Instead of a traditional union, she finds herself trapped in the arrangement, renewable every three months and contingent on nothing more than a satisfactory performance in bed.

With the introduction of the sigheh, Ms. Amirrezvani has opened up the floodgates of a murky presentism. On the one hand, our brazen protagonist is determined to defy 17th-century societal expectations — whether by adopting the male art of carpetmaking or by renouncing the bonds of her marriage. On the other, Ms. Amirrezvani is content to pinion her to the constraints of storytelling orthodoxy. Even as the narrator resigns herself to life as an unmarried woman in a man’s trade, the boldness of this conclusion hardly feels as provocative as it should because of Ms. Amirrezvani’s insistence on offering up a classic moral. The narrator’s defining epiphany, for instance, comes suddenly and bluntly: “I smiled with satisfaction. I was bold, but I was no longer rash. I finally understood the difference.”

Such preferences for the stark over the subtle, the object-lesson over the oblique, leave “The Blood of Flowers” — like the fables contained within it — to unfold as if by rote, the dictates of the conventional cautionary tale trumping the contemporary tack for which it strives. This is not to say that, by delving into Middle Eastern history, Ms. Amirrezvani has any obligation to give us social criticism rather than fiction, but that her ungainly handling of consciousness is ill equipped to engage the hypocrisies she has exposed. As the intricacy of her carpets suggests, Ms. Amirrezvani knows the aesthetic value of complexity. It is all the more unfortunate, then, that the consciousness of her characters cannot rival the glimmering surfaces of her Isfahan.

Ms. Atlas last wrote for these pages on A.M. Homes’s memoir “The Mistress’s Daughter.”