Alma is the highly intelligent and practical daughter of a wealthy botanical entrepreneur. Educated by her strict Dutch mother and granted the freedom to roam her father's massive estate of White Acre, she develops a keen scientific interest in the natural world. She approaches life with a methodical curiosity, though her focus on intellect and logic often leaves her struggling to understand human emotions.

Henry is the immensely wealthy owner of White Acre and a thriving medicinal plant business. Rising from poverty through cunning and ruthlessness, he values profit and material success above all else. He is a demanding father who favors cleverness over beauty and expects his household to run as efficiently as his global business empire.

Born to the prominent van Devender family of Amsterdam, Beatrix is a highly educated woman who manages the Whittaker household with rigorous discipline. She values intellect and industry, firmly believing that work is its own reward. She imparts her no-nonsense philosophy to her daughters, routinely cataloging their flaws to encourage self-improvement.

Ambrose is an artist and botanical illustrator who travels through Central America studying orchids. Unlike the practical Whittakers, he is deeply spiritual and believes the natural world contains divine codes meant to elevate humanity. He possesses a gentle, sensitive disposition that contrasts sharply with the aggressive business environment of White Acre.

Hanneke is the stern Dutch housekeeper who accompanies Beatrix to the United States. She serves as a surrogate maternal figure for Alma, offering the physical comfort and blunt advice that Beatrix refuses to provide. She sleeps in a fortified basement room and maintains a vigilant watch over the entire Whittaker family.

Born to an estate worker, Prudence is adopted by Henry and Beatrix when she is young. She possesses extraordinary physical beauty but maintains a cool, distant, and exceptionally polite demeanor. She focuses entirely on self-improvement and usefulness, keeping her internal thoughts and desires completely hidden from her adoptive sister.

Retta is the wealthy, largely unsupervised daughter of a neighboring Philadelphia family. She introduces an unprecedented element of play into the strictly managed lives of Alma and Prudence. She cares little for education or industry, preferring fashion, carriage rides, and lively social engagements.

George is a botanical publisher in Philadelphia who prints scientific papers. He respects academic rigor and provides a professional outlet for amateur scientists to share their findings with the broader community.

Arthur is a tutor hired to educate Prudence and Alma. He harbors strong political convictions and introduces his students to arguments regarding human rights and social justice.

Dick is Henry Whittaker's tall, bald, and generally silent man of business. He handles the practical and sometimes unsavory aspects of Henry's global enterprises, executing his orders without question.

Reverend Welles is a British missionary stationed in the South Pacific. He takes a remarkably tolerant and serene approach to his religious duties, integrating into the local community rather than strictly enforcing orthodox dogma.

Also known by his Tahitian name Tamatoa Mare, Tomorrow Morning is an orphaned local who was raised by the mission. He grows into a charismatic and highly successful leader within the community.

Dees is Beatrix's younger brother and a prominent figure at the Hortus Botanicus in Amsterdam. He carries on his family's long tradition of managing the historic botanical gardens.

Sir Joseph is a wealthy, world-traveled botanical explorer and the superintendent of Kew Gardens. He recognizes raw ambition and sets a young Henry on his path to fortune by sending him abroad.