Monocotyledons are rare, the only ones of much interest being some fragments of pandanaceous leaves.
In Monocotyledons, as in grasses, there is often only one, while in Dicotyledons they number from three upwards; when numerous, the pores are either scattered irregularly, or in a regular order, frequently forming a circle round the equatorial surface.
In albuminous Monocotyledons the cotyledon itself, probably in consequence of its terminal position, is commonly the agent by which the embryo is thrust out of the seed, and it may function solely as a feeder, its extremity developing as a sucker through which the endosperm is absorbed, or it may become the first green organ, the terminal sucker dropping off with the seed-coat when the endosperm is exhausted.
Sometimes, as usually in monocotyledons, the calyx and corolla are similar; in such cases the term perianth, or perigone, is applied.
The symmetry which is most commonly met with is trimerous and pentamerous - the former occurring generally among monocotyledons, the latter among dicotyledons.