Can all monoecious plants with imperfect flowers self-pollinize themselves and with other plants?

Question

Or are some only limited to other plants, etc.? examples of each?

Answer 1

Imperfect flower. A flower that is either male or female due to its missing of either reproductive organ.
Monoecious. Plants having both male and female flowers on the same plant.

All monoecious flowers are imperfect. That means they are either male or female, not both. In order for them to be pollinated they need to receive the pollen from the male flower. Whether it be from the same plant or another near by it makes no difference. The female flower is incapable of fertilizing itself.

Examples: Alder, Birch ,Chestnut, Hickory, Cedar, Fig, and Walnut