bio

Angiosperm

The flowering plants — the largest group of plants today, and the most recent of the major groups. They spread across terrestrial habitats in the Early Cretaceous, around 135 million years ago, so abruptly that Darwin called it an "abominable mystery". Three features account for much of the success: ovules fully enclosed in a folded megasporophyll (the carpel); double fertilisation, meaning nutritive tissue for the embryo is built only after fertilisation succeeds, so nothing is spent on ovules that fail; and vessel elements with open perforation plates, which carry sap faster than gymnosperm tracheids. Worth remembering: seagrasses are angiosperms, not algae.