A buttonhole, called a boutonnière in the US and bottoniera in Italian, is a single flower or a small cluster of flowers and foliage fixed to the lapel with a pin or a magnet. The groom almost always wears one; often so do the witnesses, the fathers and sometimes close friends. It echoes the bridal bouquet without copying it.
It has to last many hours out of water, so it uses sturdy flowers, foliage and sometimes preserved flowers. The guide on buttonholes and flowers for the groom covers flowers, sizes and fixings; the one on how much a bouquet costs gives indicative ranges; at an elopement it may be the only flower besides the bouquet, as the guide to eloping in Italy explains.
What to ask: how many you need, how they are fixed, and who pins them on in the morning.
