Question
I have an orchid stem with flowers and buds in a bouquet.  Can I do something to start a plant with this stem ?

Answer
Janet, I'm assuming that you are referring to the flower spike of a phalaenopsis orchid-- the most common type. While I can't rule out the possibibility, it is highly unlikely that you can root an orchid spike that has been severed from the plant. Unlike the cutings from many house plants, orchids need a node or joint in the flower spike and a flow of hormones from the mother plant to induce growth at a node.