Monoporate grains
Earth History Research Center

The simple monoporate grain consists of a spherical, often thin-walled and rather large grain, with a single pore. These grains characterize the grasses, one of the largest and most diverse families of monocotyledonous plants. The grasses include everything from wheat and other cereal grains to sugar cane and bamboo, which can extend upward 100 feet in the air, and have a diameter of a foot or more at the base.

The grain shown here is from a common brome grass, but it has little to distinguish it form a horde of other similar grains. Monoporate grains are not common below Oligocene in the mid Tertiary, but may occur as far back as Cretaceous.