Untersuchungen zur Blatt- und Blütenentwicklung bei Galium aparine L. (Rubiaceae)

Abstract

Summary The development of the leaves and flower of Galium aparine was studied using microtome technique and the scanning microscope. The leaves develop from decussated primordia in a way which is typical of dicots. Simultaneously two common meristems emerge between them which divide into different numbers of primorida which, in turn, result into the phyllomes mostly referred to as stipules. Differences in the initiation at the shoot apex and a slight advance of the growth of leaf primordia are the only characters to discriminate the morphogenesis of different phyllomes of a whorl. The two to seven flowers of partial inflorescences develop successivly. The differentiation of the floral shoot apex begins with the simultaneous occurrence of the petal and staminal primordia. The inferior gynoecium produces a synascidiate and a symplicate zone developing placentas and ovules at an early stage of the development. Rudimentary sepal primordia were not detected.