PLant looks like a cucumber but the seeds don't. You may have to wait till it fruits.

Reminds me of the wild cucumber weeds that grow here, but the flowers on that are single.

Maybe a Mexican sour gherkin?

Mexican sour gherkin flowers are borne singly, and are tiny and yellow. The seeds are also tiny and are white.

The plant in question appears to be a loufah gourd.

Rodney

Are the yellow flowers back left part of the same plant? Has it produced any fruit yet? It reminds me strongly of a Bryonia species.

At first glance this could be mistaken for a plant stem but it sure looks like a female flower with embryonic fruit to me. :-)

Rodney

Yes it does. Bud clusters are right too.

QED.