When the world's first flower sprouted about 140 million years ago, it was bisexual, possessing both male and female reproductive parts ... evolutionary tree — a diagram showing relationships ...

Even though textbook diagrams show male and female flower parts snugged into a single blossom, plants vary enormously in terms of sex and blooms, with important implications for agriculture.

Most plants have flowers, and these flowers can be male, female, or both. The male parts of a flower are called stamens, ...