Nutation (botany) flowers to open or close by movements which resemble the simple nutation of dorsiventral organs. Thus, the tulip, crocus, and other vernal flowers are very sensitive to changes in temperature. The crocus can perceive a change of 0.5°C (0.9°F), and will respond to a change of 20°C (36°F) in two minutes. Nutation (botany) Nutation is the bending movements executed by some plant organs, such as stems, leaves, roots, etc., by which the part is inclined successively in various directions. Nutations are due to the unequal rate of growth of different sides of the organ, an inequality which, so far as
History of botany books, known as herbals showed that botany was still a part of medicine, as it had been for most of ancient history. Authors of herbals were often curators of university gardens, and most herbals were derivative compilations of classic texts, especially "De Materia Medica". However, the need for accurate and detailed plant descriptions meant that some herbals were more botanical than medicinal. German Otto Brunfels's (1464–1534) "Herbarum Vivae Icones" (1530) contained descriptions of about 47 species new to science combined with accurate illustrations. His fellow countryman Hieronymus Bock's (1498–1554) "Kreutterbuch" of 1539 described plants he found in nearby woods and