Pentamerous, actinomorphic flowers, bicarpellary ovary with oblique septa, and fruit a capsule or berry, are characteristic features of -

Solanaceae is commonly called the potato family.
Its flowers are bisexual, actinomorphic and pentamerous: five united sepals, five united petals and five epipetalous stamens.
The gynoecium is bicarpellary and syncarpous, with a superior, bilocular ovary; the placenta is swollen and bears many ovules in axile placentation.
A special feature is that the ovary is obliquely placed, so the septum is oblique.
The fruit is a berry (tomato, brinjal) or a capsule (Datura, tobacco).
Brassicaceae has tetramerous flowers and a siliqua, Liliaceae has trimerous flowers, and Asteraceae has a head inflorescence with a cypsela fruit.
So these are the characteristic features of Solanaceae.