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 northern Italy, the first being at Pisa (1544), founded by Luca Ghini (1490–1556). Although part of a medical faculty, the first chair of ', essentially a chair in botany, was established in Padua in 1533. Then in 1534, Ghini became Reader in ' at Bologna University, where Aldrovandi established a similar garden in 1568 (see below). Collections of pressed and dried specimens were called a "" (garden of dry plants) and the first accumulation of plants in this way (including the use of a plant press) is attributed to Ghini. Buildings called herbaria housed these specimens mounted on card with