How many of the given plants have marginal placentation:Pea,gram,sem,tomato,marigold,Indigofera,lupin,sweet pea,Petunia,tobacco,asparagus,tulip.
Pea, gram, sem, Indigofera, sweet pea and lupin belong to family fabaceae and show the characters like diadelphy, marginal placentation and vexillary aestivation of corolla.