We Go Way Back (Plant Version)
Many plant species living among us now are remarkably ancient. Among them:
Sunday
The ginkgo biloba tree isn’t just remarkable for being a 200 million year-old species. It is the only living member of its species, individual trees can live well over a thousand years, it has a massive (but largely repetitive) genome, it is the only tree on Earth with fan-shaped leaves, and ginkgos growing 1/2 mile from Hiroshima’s bombing survived the atomic blast.
Monday
Ferns are common, but also ancient, with a 380 million year history on Earth. This plant group predates the evolution of seeds, grass, and flowers, and prehistoric fern trees were a major food source for the dinosaurs. They can reproduce both sexually and asexually, and their leaves unfurl as they grow.
Tuesday
There are only a handful of Wollemi pines left in the world, but the species has history. The 91 million year-old species comes from a 200 million year-old plant family, and like so many “living fossil” plant and animals, they were believed long extinct before a very small group was discovered in a rainforested valley in Australia. With fewer than 100 individuals, however, the species is critically endangered.
Wednesday
Aptly-named horsetails descend from ancestors which grew tall and thick in forests 350 million years ago. Though the modern relatives are shorter, they’ve adapted well to modern Earth and grow on every continent but Antarctica, and the 15 species now alive now are the only members of the genus Equisetum.
Thursday
While some prehistoric plants predate the evolution of the seed, cycads are an ancient cone seed plant with a history predating the dinosaurs. They aren’t true palms, but are sometimes named that from a superficial similarity. Today over 300 species are still around, though in the Jurassic Period they were so diverse as to constitute 20% of the world’s flora.
Friday
After starting about 200 million years ago in the Triassic Period, sequoias dominated the tree population of Europe and North America while the dinosaurs roamed around. Now that the earth is cooler than in the Jurassic, these massive trees are mostly found naturally growing on the west coast of North America. Giant Sequoia is the largest tree species on modern Earth, with the oldest known specimen at least 3,200 years old.
Saturday
Takakia is a moss genus with only two surviving species, and scientists believe these branched off from their extinct ancestor 390 million years ago. If true, this tiny plant has lived on our planet longer than any other yet discovered.