Cucurbits are monoecious; there are separate male and female blossoms on the same plant. The male flowers tend to open first, followed by the female flowers. It is only when both the male and female flowers are open that pollination can occur.
There is nowhere in the Constitution that says that the Congress can subpoena the President of the U.S. or his people. Congress does however have general subpoena powers, but they are not absolutely clear. There are Supreme Court cases that speak to this. They generally limit this to national security type of issues.
no, congress can not directly vote to overturn an executive order. congress must pass a bill cancelling or changing the order in the manner they see fit, the president will most likely veto the bill, and then congress can overrule the veto by 2/3 vote.