Asplenium × ebenoides facts for kids
Quick facts for kids Asplenium × ebenoides |
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| Scientific classification | |
| Genus: |
Asplenium
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| Species: |
× ebenoides
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| Synonyms | |
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×Asplenosorus ebenoides (R.R.Scott) Wherry |
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The Asplenium × ebenoides fern is also known by fun names like Scott's spleenwort, dragon tail fern, or walking spleenwort. This special fern is a hybrid, meaning it's a mix of two different ferns. It grows naturally in eastern North America.
This fern is a cross between the walking fern (A. rhizophyllum) and the ebony spleenwort (A. platyneuron). It looks a bit like both its parents! It has the long, narrow leaves of the walking fern, but with a dark stem and leaf parts (called lobes or pinnae) similar to the ebony spleenwort.
Most A. × ebenoides ferns are sterile, meaning they can't make new ferns from their spores. But some special ones found in Havana Glen, Alabama, can reproduce. These fertile ferns have double the usual number of chromosomes. In 2007, these fertile ferns were given their own species name, A. tutwilerae. The name A. × ebenoides is now only used for the sterile (non-reproducing) ones.
Scientists first thought A. × ebenoides was a hybrid in 1862. But back then, many didn't believe that ferns could mix like that. The discovery of the fertile ferns in Alabama in 1873 made things even more confusing!
In 1902, a scientist named Margaret Slosson grew A. rhizophyllum and A. platyneuron together in a lab. She successfully created ferns that looked exactly like A. × ebenoides. This was a big step in proving that fern hybrids really exist. Later, in 1957, Herb Wagner and Robert S. Whitmire even managed to turn the sterile A. × ebenoides into a fertile form in the lab. This was the first time anyone had created a fertile hybrid fern in this way!
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What Does Asplenium × ebenoides Look Like?
Asplenium × ebenoides is a small fern that stays green all year. It likes to grow on rocks in small groups. Its leaves grow from a dark, shiny stem. The leaves have a varied and irregular shape.
The lower part of a leaf might be deeply cut into small parts called pinnae. The upper part of the leaf is more lobed and ends in a sharp point. Sometimes, this tip can even form a tiny bud that might grow into a new plant! Some of the fern's leaves are slightly different, with the fertile ones being a bit bigger and standing more upright.
Stems and Roots
The fern's roots are thin, about 1 millimeter wide. They grow straight up or at an angle. They are covered with dark brown or black scales, which are tiny and shaped like triangles.
The stem of the leaf, called the stipe, is shiny and reddish-purple. It can be from 1 to 10 centimeters long. The scales from the roots continue up the stipe, getting smaller and turning into tiny hairs higher up. The stipe can be anywhere from 20% to 100% of the leaf's total length.
Leaves and Blades
The fern's leaf blades can spread out or stand upright. The fertile leaves are usually a bit taller. The overall shape of the blades is like a narrow triangle, from 2 to 20 centimeters long and 1 to 6 centimeters wide.
The shape of the leaves can change a lot. The bottom third of the leaf might be fully cut into separate pinnae. There are usually no more than three pairs of pinnae. The upper part of the leaf is more lobed and ends in a sharp, straight tip. The leaves have a few soft hairs on their top surface.
The main stem of the leaf, called the rachis, is shiny and smooth. It's reddish or purplish-brown at the bottom and turns green towards the tip. The pinnae, if present, are triangular and can be from 5 to 30 millimeters long. Their edges can be smooth or have small teeth.
Spores and Reproduction
On the underside of the leaves, you'll find the veins. The fertile leaves have small brown spots called sori. These sori contain the spores. In A. × ebenoides, the spores are usually not fully formed and can't grow into new plants. However, very rarely, some viable spores can form.
The sori are about 1 to 2 millimeters long and are covered by thin, whitish covers called indusia. The very tip of the leaf sometimes has a bud, just like the walking fern. These buds can grow into tiny new plants, but they usually don't take root in nature.
How Is It Different from Other Ferns?
The fern that looks most like A. × ebenoides is A. tutwilerae. They look so similar that for a long time, scientists thought they were the same! The main way to tell them apart is by their spores. A. tutwilerae has 64 healthy spores in each spore case, while A. × ebenoides has sterile, malformed spores.
In the wild, A. × ebenoides might also be confused with A. pinnatifidum. But there are a few key differences:
- A. pinnatifidum has a green stem and rachis, only purple at the very bottom. A. × ebenoides has more purple.
- The lobes of A. pinnatifidum are more regular.
- A. pinnatifidum is widest at its base, while A. × ebenoides is widest a bit above the base.
Where Does Asplenium × ebenoides Grow?
Asplenium × ebenoides is found only in eastern North America. You can find it from Alabama in the south, up to New Hampshire in the north, and as far west as Missouri and Arkansas. It's scattered across the Appalachian Mountains and the Piedmont region. It also grows along the Ohio Valley and into the Ozark Mountains.
This fern always grows in places where both its parent ferns (walking fern and ebony spleenwort) are also found. The fertile form, A. tutwilerae, has only been found in Hale County, Alabama, so far.
Where Does It Live?
Asplenium × ebenoides is a rock-loving fern. It grows on many different types of rocks where its parent species live. It's common on limestone, but it has also been found on gneiss, schist, shale, and sandstone. The closely related A. tutwilerae grows on a type of rock called conglomerate.
This fern prefers slightly acidic conditions. It typically grows on rock faces and cliffs, at heights from about 70 to 500 meters (230 to 1,640 feet) above sea level.
Growing This Fern
Sometimes, people grow A. × ebenoides in greenhouses or gardens because it's a pretty plant. To help it grow best, it needs moist soil, or soil mixed with small rock chips. It also likes medium light and lots of humidity.
If you buy A. × ebenoides from a garden center and it was grown from spores, it's likely the fertile form, which is now called A. tutwilerae. This fern has become quite popular and is sometimes sold as "Dragon's-Tail Fern."
