Androecium 6–36. Androecial members free of the perianth; united with the gynoecium (forming a gynostemium by fusion to the style of the filaments, or of both the filaments and the anthers), or free of the gynoecium; free of one another, or coherent (via the gynostemium); when joined, 1 adelphous; 1 whorled, or 2 whorled. Androecium exclusively of fertile stamens. Stamens 4, or 6 (commonly), or 12(–36); isomerous with the perianth to polystemonous; filantherous, or with sessile anthers. Anthers cohering, or separate from one another; basifixed, or adnate; non-versatile; dehiscing via longitudinal slits; extrorse, or extrorse and introrse (Heterotropa); tetrasporangiate; appendaged (apically, with the expanded connective assuming stigmatic functions in association with the gynostemium), or unappendaged. Endothecium developing fibrous thickenings. Anther epidermis persistent. Microsporogenesis successive, or simultaneous. The initial microspore tetrads tetrahedral, or isobilateral, or decussate, or T-shaped (rarely). Anther wall initially with more than one middle layer; of the ‘dicot’ type. Tapetum glandular. Pollen shed as single grains. Pollen grains aperturate, or nonaperturate; 1–7 aperturate; sulcate, or sulculate (monosulcate to multisulcoidate or sulculate); 2-celled.