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
Plant life-form plant functional type, which has recently replaced "life-form" in a narrow sense. Following, some relevant schemes. Based on plant habit: Humboldt described 19 (originally 16) "Hauptformen", named mostly after some characteristic genus or family: Based upon the duration of life and the height of the ligneous stem: Based on the place of the plant's growth-point (bud) during seasons with adverse conditions (cold seasons, dry seasons): Vegetation-forms: Main life-forms ("Grundformen") system: Growth-form system: Main groups of plant life forms: Following, other morphological, ecological, physiological or economic categorizations of plants. According to the general appearance (habit): According to leaf hardness, size and