On a recent afternoon, Ina Vandebroek was poking around the shelves of La 21 Division Botanica on the Grand Concourse in the Bronx. Its narrow aisles were crammed with thousands of votive candles, herbal potions and brightly colored plaster statues of saints.

Dr. Vandebroek, a Belgian-born ethnobotanist, paused to gaze at herb-infused oils. The vials had names like Amor Prohibido (“Forbidden Love”), for those in search of adventure, and Conquistador, for the timid — both of them big sellers. Bendicion de Dinero Al Hogar (“A Blessing for Money in the House”), which comes in a spray, is also popular. But Dr. Vandebroek was not there to jump-start a flagging love life or curry the favor of spirits. La 21 Division is a regular stop for her, a mile or so from her laboratory at the New York Botanical Garden, where she is the assistant curator of economic botany.

She is conducting a multiyear study of the folk remedies sold in New York’s botanicas, more than 100 emporiums that offer products for all that ails the body, mind and soul to a clientele mainly consisting of Latino and Caribbean immigrants. She is compiling guides in English and Spanish describing the plants and their uses. Her goal is to promote “culturally effective and sensitive health care” for a community that is chronically underserved by mainstream medicine.

“I came to NYC in 2005 and expected immigrants from the Caribbean to use very few plants for health care because most of the medicinal plants they know from their home countries don’t grow here,” she said in an email. Instead, she was amazed to find that Dominicans in New York, for example, use more than 200 plant species for medicinal purposes.