In
angiosperms, a
hypanthium or
floral cup is a structure where basal portions of the
calyx, the
corolla, and the
stamens form a cup-shaped tube. It is sometimes called a
floral tube, a term that is also used for
corolla tube and
calyx tube. It can often contain the
nectaries of the
plant. It is present in most flowering species, although varies in structural dimensions and appearance. This differentiation between the hypanthium in particular species is useful with
identification. Some
geometric forms are
obconic shapes as in
toyon, whereas some are saucer-shaped as in
Mitella caulescens.