Microspermae

Microspermae is an order of flowering plants. It is a descriptive botanical name referring to the size of the seed; it was used for the order containing the orchids. 
In taxonomical systems this name has now mostly dropped out of use, being displaced by the name "Orchidales" (formed from the family name "Orchidaceae"). The name "Microspermae" was used in the Bentham & Hooker and the Engler systems. The Wettstein system also used a descriptive name, but preferred "Gynandrae".