Q: I am hoping you can tell me what the plant shown on the attached pictures is.

It is a volunteer that grows with gusto. It’s blossoms open at night and close in the morning. As you can see it is spreading everywhere except on the lawn.

A: Some people have trouble growing gourds and here you have one that volunteered and looks very happy!

No telling where it came from. Do you have a gourd birdhouse nearby?

It’s probably a calabash gourd or bottle gourd. Gourds of this type have white flowers that open at night, to attract pollinating moths, unlike squash and melons, whose flowers open in daylight.

See
Harvesting Gourds