The anther is a morphologically simple organ of the flower concerned with some unique functions, such as microsporogenesis and the production of pollen grains. The size, shape, and orientation of the anther on the stamen and the diversity of the cells and tissues of the anther make it a morphogenetic system of great interest. A typical anther is a two-lobed organ with two locules or microsporangia in each lobe and, so, the anther is functionally a group of four microsporangia. A single vascular strand is embedded in the connective, which is the tissue found in the central region of the anther between the two lobes. In most plants, anthers are readily accessible to observations and manipulations; for these reasons, and in recognition of their role in the sexual reproduction of plants, anther developmental biology is one of the most extensively studied topics in plant embryology. Over the years, the goal of these studies, aptly termed “classical,” has been to gain insight into the mechanisms by which the anther reacts to developmental information communicated to it. As a result, there has been an accumulation of considerable data on the histology underlying the differentiation of specialized cells and tissues of the anther and the physiology of anther growth, as well on the isolation and characterization of genes preferentially expressed during anther development.