Herbarium stories: Pressed plants, a portal to the past, a window into evolution

In a small room tucked inside the International Potato Center’s (CIP in Spanish) biodiversity complex, the faint scent of flowering potato plants lingers. Nimble fingers work to adhere pressed samples of potato, sweetpotato and Andean roots and tubers to acid-free paper. Each new addition not only adds to the CIP Herbarium’s growing collection, it adds to the world’s understanding of root and tuber crops.

Hidden in these pressed flowers, leaves, and stems are the unfolding stories of plant evolution. Each specimen is a faithful witness of the environment in which it grew. As a collection, they provide a treasure trove of information on the breadth of plant diversity and allow scientists to understand how these species have evolved in the face of changing environmental pressures.

The CIP Herbarium houses almost 22,000 accessions. Each one lovingly collected and painstakingly preserved from the most remote corners of the world. Here are some of their stories.

Dr. Carlos Ochoa

Behind every specimen housed in the herbarium is a collector. Over the course of his lifetime, intrepid explorer Dr. Carlos Ochoa collected and described 80 species of potato wild relatives and produced two authoritative books about potato species across the Americas. After a lapse of 31 years, Ochoa retraced his steps to kilometer marker 38 on the Cerro de Pasco-Huanuco highway, where he originally collected a Solanum ambosinum sample OCH1040.  Reaching the collection site meant crossing the Huascar River whose water level rose considerably in the time it took him to gather the material he needed.. Much like Alberto Salas, his colleague, Dr. Ochoa almost lost his life trying to reach safety.  Unpredictable rivers are just of one of the life-threatening challenges that collectors like Ochoa and Salas have faced over the years.