Today, there are over 250,000 species of flowering plants. One hundred thirty million years ago, there were none. Where did they all come from?
No one knows. Charles Darwin described the origin of flowering plants as an “abominable mystery.” These plants evolved so rapidly that sorting out the relationships between existing groups has proven to be quite tricky.
Some of the most primitive flowers today, water lilies and lotuses, live in fresh water habitats. Likewise, the earliest flower fossil was also an aquatic species. It grew in China some 125 million years ago. Other early fossils also point to a watery origin for flowers.
The origin of these plants, however, remains a mystery. Some scientists point to Glossopteris, as a likely ancestor, as its leaves are very similar to those of modern flowering plants. However, Glossopteris went extinct between 180 and 230 million years ago, leaving a large gap between it and the first flower.
“Flowering plants” include more than just your garden-variety daisies and petunias. Grasses, grains, fruits, nuts and leafy trees are also angiosperms (AN-gee-oh-sperms), the scientific name for this group. What they have in common are seeds surrounded by some sort of food source.
The Palomar College Arboretum has a fun page on the diversity of flowering plants.