cleistogamous

Finely puberulent; leaves mostly ovate and acutish with a cordate base, often small; flowers small and mostly cleistogamous.—Sandy or stony shores and islands of Lakes Huron and Superior.

Amphicarpum, native in the south-eastern United States, has fertile cleistogamous spikelets on filiform runners at the base of the culm, those on the terminal panicle are sterile.

Every plant which produces these cleistogamous or bud-fertilized flowers bears also more conspicuous and open flowers, usually of bright colors.

In other cases precautions are taken to prevent cross-fertilisation, as in the numerous cleistogamous or closed flowers.

The beech-drop bears cleistogamous or blind flowers in addition to the few showy ones needed to attract insects.