Tetradynamous stamens are characteristic of :

Tetradynamous condition is observed in Brassicaceae family. In tetradynamous condition outer 2 stamens are short and inner four are long.Diadelphous condition (9 fused stamen and 1 stamen free) is observed in Fabaceae family. Epipetalous condition (Stamens fused with petals) is observed in Solanaceae family.Epihyllous condition (Stamens fused with perianth) is observed in Liliaceae family.