All about Ferns

10/6/2017

What are ferns? Where do they grow? How do they reproduce? What kind of fern is this? How long have they been around?
We've all seen ferns, wether it's in the woods or in a local plant nursery, but what do you really know about these unique creatures from a long lost time?

How long have ferns been around?
Ferns first appeared roughly 360 million years ago, although the ferns we know today evolved around the time of the t-rex and triceratops during the cretaceous period 145 million years ago.

What are they?
They are a vascular plant meaning they have certain tissue that conducts water and nutrients throughout the plant. They have no flower or seeds and reproduce through spores.

Where do they grow?
While we're familiar with the ferns of moist shady forests, ferns can be found all over the world - high mountaintops, dry desert rock faces, in bodies of water, even in tropical trees. What determines where a type of fern will grow is dependent on the PH levels of the soil. In the highly acidic soil of bogs you can find lots of ferns!

What are those tiny spots under the leaves?
Those are the sporangia, tiny pods that hold the spores until mature. Once mature the ferns need either a big gust of wind or a rainstorm to allow the spores to be released from the sporangium. Not all ferns have the sporangia arranged in spots, sometimes they appear as solid lines under the leaf, sometimes as a solid border around the leaf, and in other cases you won't find any under the leaf - instead, usually early on, the plant will send up a fertile frond (often looks like a stick sticking up with a cluster on the end), the cluster is a modified pinnae where the sporangia can grow and release spores. Cinnamon Ferns get their names by the appearance of these fertile fronds.

Parts of a fern.
From the ground up, ferns form from a Rhizome in the ground, the Rhizome grows the Petiole or Stipe (stem of the fern before it branches or forms the blade), from the Petiole (Stipe) comes the Rachis (the part of the original stem that has the green).
The Rachis is then broken down into a few different terms based on how the individual parts are attached. Pinnae and Pinnules are the primary and secondary divisions of the blade. The Veins are the thread-like vascular elements in the leaf tissue that define patterns. The Pinnae can have a wide range of edges - entire, crenate, serrate, dentate, and undulate.
It sounds complicated, but check out the handy diagram from the University of Georgia below.

How do I tell what kind of fern this is?
Now that you know the different parts of the fern, by observing each part closely and noting the environment with which it's growing, you'll be able to grab a field guide and decipher just what type of fern you have. It's very important to note everything down to the hairs or scales on the stipe to make a 100% proper ID.
However, in our parts there are some unique and easy to ID ferns.
All of the ferns listed grow in moist shady forests.
Cinnamon Fern - Tall up to 5ft, early fertile frond resembling a cinnamon stick. 1-pinnate, deeply pinnatifid.
Christmas Fern - Evergreen, Pinnae can be described as looking like stockings (Christmas stocking).
Sensitive Fern - What I call 'wobbly leaves'- sterile leaf deltoid-ovate, coarsely segmented, up to 2ft long. AKA Bead fern due to structure of sterile leaf.
Royal Fern - Disguised as a small locust tree, ovate-lanceolate leaf. Fertile frond gives this fern its common name 'flowering fern'.