The anthers are called introrse when they dehisce by the surface next to the centre of the flower; they are extrorse when they dehisce by the outer surface; when they dehisce by the sides, as in Iris and some grasses, they are laterally dehiscent.
The sporangia, which arise in basipetal succession on the receptacle, dehisce by a median slit, though the annulus is somewhat oblique; they have resemblances to the Gleicheniaceae.
The anthers dehisce at different periods during the process of flowering; sometimes in the bud, but more commonly when the pistil is fully developed and the flower is expanded.
They either dehisce simultaneously or in succession.
From these masses of ova dehisce into the body cavity and float in its fluid.
The sporangia dehisce by a transverse slit, the annulus being truly vertical or, in some of the genera in which they are regularly arranged, very slightly oblique.