In 1927 she joined the
phytography section of the
Real Jardín Botánico de Madrid. As a curator, she was dedicated to the study of native Spanish grasses. In 1948 she created the agrostology laboratory, becoming head of it. She also taught at the University of Madrid from 1940 on phytography and botanical geography and also, from 1941 to 1949, on plant ecology. In 1962, Ruiz became head of the Herbarium Section of the Botanical Garden. Following a change in director to the Botanical Garden, Ruiz (who was close to the previous director and seen as his "right hand") felt increasingly uncomfortable with changes made to the garden. This motivated her to retire early. ==Personal life==