Monandrous
In botanical terms, monandrous simply means to have a single stamen.
A distinction between monandrous and other flowers is particularly relevant in the classification of orchids. The monandrous orchids form a clade consisting of the subfamilies Orchidoideae, Vanilloideae, and Epidendroideae. The other subfamilies, Apostasioideae and Cypripedioideae, have at least two stamens.