How old are ferns?
Happy birthday to a sweet friend of mine. She's an Earth lover... forest wildflowers, ferns and goats were on her list for Birthday Doodle ideas. So precious, right? I did think about trilliums and wild lady slippers because it's Morel season... but I I have been paying attention to ferns lately, so that's what I chose.
The definition of a fern is any of a division (Filicophyta) or class (Filicopsida) of flowerless spore-producing vascular plants having alternating sporophyte and gametophyte generations. Especially: any of an order (Filicales) of homosporous plants possessing roots, stems, and leaflike fronds.
Ferns are one of the oldest groups of plants on Earth, with a fossil record dating back to the middle Devonian period, around 383-393 million years ago. Recent divergence time estimates suggest they may be even older, possibly having first evolved as far back as 430 million years ago! Ferns actually fourished over 300 million years ago; plants with fern-like leaves and ferns were so abundant in ancient tropical swamp forests that this time has been called “The Age of Ferns.” So ferns are older than dinosaurs!! That being said, most of those earliest ferns have gone the way of the dinosaurs... extinct. The ferns we see today evolved relatively recently (in geologic time), many of them evolved in the last 70 million years.
Today, ferns are the second-most diverse group of vascular plants on Earth, outnumbered only by flowering plants. With around 10,500 living species, ferns outnumber the remaining non-flowering vascular plants by a factor of 4 to 1. Modern-day ferns are exquisitely diverse in size, shape and leaf-form; from magnifcent 30-foot tall tree ferns to the diminutive hairy water-clover, with its 4-leaf clover leaves. In some genera (e.g. Lygodium and Salpichlaena) the main leaf axis twines about on shrubs and small trees, sometimes reaching 65 feet in length.
Most ferns have rhizomes, which are underground stems from which the leaves are produced. Many ferns have long, creeping rhizomes that form intricate networks underground, and while the leaves may drop off due to age or cold weather, these rhizomes can persist indefinitely, sending up new leaves year after year.
Though most ferns species grow in tropical climates, there are approximately 380 kinds of ferns in North America and almost all of those varieties can be found on the national forests and grasslands. Ferns are adapted to nearly all environments—forests, deserts, tropics, alpine and aquatic. Similar to fowering plants, ferns have roots, stems and leaves. However, unlike fowering plants, ferns do not have fowers or seeds; instead, they reproduce sexually by tiny spores or reproduce vegetatively, as illustrated by the walking fern.