Floraison et réversion chez Sinapis alba. II. Caractères morphologiques de plantes porteuses de réversions

Abstract

When plants have been submitted to a short inductive phase, then to a long dysperiodic phase, and finally to inductive conditions again, one or several branches, with or without subtending leaves, develops on some inflorescences above a series of flowers. These branches constitute a morphological inflorescence reversion, and the axis which carries them is called "α axis." Maximal vegetative characteristics are found at the basal part of a reversion. When several consecutive axes are a axes, the most vegetative reversion (maximal reversion) is developed on the lowest of these axes. Some more or less abnormal structures, such as a series of bracts, an axis with a "terminal" flower, proliferated flowers, or virescences, are sometimes inserted between typical flowers and branches on the edge of the reversed region.Apart from inflorescences, some gradients are different from those shown by plants maintained in inductive conditions: the slope of the "axillary relativity" curve is reversed, and the final length gradient of the six upper leaves of the main axis is attenuated.