With 51 years Ynes Mexia began a Botany degree from the University of California, Berkeley. In 1925, she started her career as a plant collector with a trip to Mexico. In the next thirteen years, she has made numerous research expeditions to Mexico, Brazil, Peru, Chile, Ecuador, Colombia, Argentina and Alaska where they collected approximately 150,000 plants, more than 500 of them unknown until then.
She held lectures and slide presentations about their research results and published regularly in botanical journals such as " Madroño ". She was a member of the California Botanical Society, the Sierra Club, the Audubon Association of the Pacific, the Sociedad Geografica de Lima, and the California Academy of Sciences, where her collection is housed. She was also named an honorary member of the " Departamento Forestal y de Casa y Pesca de Mexico ".
In 1938 she became ill on one of their expeditions to Oaxaca and Guerrero in the south-west Mexico and had to turn back. She died on 12 July 1938. Discovered by The Ynes Mexia species Mimosa mexiae and Mexianthus mexicanus were named after her.
Writings (selection )
- Botanical Trails in Old Mexico (1929 )
- Brazilian ferns collected by Ynes Mexia (1932 )
- Three Thousand Miles Up The Amazon (1933 )
- Camping on the equator (1937 )
Ynes Mexias Botanical collection is housed in the California Academy of Sciences. In addition, located in many research centers of botany offshoot of its collection of plants, such as the Academy of Natural Sciences ( Philadelphia ), the Field Museum of Natural History, ( Chicago), the Gray Herbarium, Harvard University, the University of California, ( Berkeley ) trädgården and many important museums and botanical gardens, including the Royal Botanic gardens (London), Jardin des Plantes (Paris), Botanisk Have ( Copenhagen), Bergianska (Stockholm), the Old Botanical Garden ( Zurich ) and the Conservatoire et Jardin botaniques (Geneva).
Their records are in the California Academy of Sciences and the Bancroft Library, Berkeley.