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
Astrological botany Virgo. Astrological botany was often used in conjunction with the doctrine of signatures, which held that the physical form of a plant reflected its medicinal use. In the words of Agnes Arber, England became "badly infected" with astrological botany during the 17th century, when its most "notorious" practitioner was Nicholas Culpeper. Astrological botany Astrological botany is based on the notion that if plants or seeds are to be used for medicinal purposes then their planting and collection must be carried out with regard to the positions of the planets and other heavenly bodies, which are at the heart of the