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.
The Constitution explicitly assigns to the president the power to sign or veto legislation, command the armed forces, ask for the written opinion of his Cabinet, convene or adjourn Congress, grant reprieves and pardons, and receive ambassadors.f the president kills a bill in this manner there is nothing that Congress can do to override this, which is called a  pocket veto . When signing a bill the president can also issue a signing statements that expresses his opinion on the constitutionality of a bill's provisions that intrude on executive power.