Androecium: stamens 4-5(-12), isomerous, alternipetalous, sometimes strongly zygomorphic and adnate to corolla tube or mouth, rarely some staminodal or even obsolete (Hoppea): anthers tetrasporangiate, usually introrse (extrorse in Gentiana) and dithecal; dehiscing via a longitudinal slit or rarely by terminal pores (Exacum); occasionally connate (Voyria); occasionally connective with one to two apical glands (Sebaea); rarely with long thread-like projections (Urogentias).
Androecium: stamens isomerous, alternipetalous and adnate to corolla-tube; anthers tetrasporangiate and dithecal, dehiscing via longitudinal slits; connective forming a small apical point.