Hairy false cloak fern facts for kids
Quick facts for kids Hairy false cloak fern |
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| Conservation status | |
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| Genus: |
Argyrochosma
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| Species: |
incana
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The Argyrochosma incana, also known as the hairy false cloak fern, is a type of fern. You can find it in the southwestern United States, all the way through Mexico to Guatemala. It also lives in a separate, faraway group in the Dominican Republic. This fern likes to grow on rocky slopes and steep banks, often in forests. Like many "false cloak ferns," it has a cool feature: white powder on the underside of its leaves. It was first described as a species in 1825. Later, in 1987, it was moved into a new group called Argyrochosma, which means "false cloak ferns." This helped show how different they were from other "cloak ferns."
Contents
What the Hairy False Cloak Fern Looks Like
The Argyrochosma incana is a medium-sized fern that grows on rocks. It has a short, thick stem underground called a rhizome. This rhizome can grow sideways or stand a bit upright. It has long, thin scales that are about 5 to 6 millimeters (0.2 to 0.2 in) long and 0.8 millimeters (0.03 in) wide. These scales are dark, shiny brown or yellowish-brown.
The fern's leaves, called fronds, grow in bunches from the rhizome. They can be 5 to 20 centimeters (2.0 to 7.9 in) long, sometimes even up to 40 centimeters (16 in). About half of this length is the stipe, which is like the leaf's stalk. The stipe is shiny, round, and usually dark purple to black. It is typically 4 to 12 centimeters (1.6 to 4.7 in) long and 0.75 to 2 millimeters (0.030 to 0.079 in) thick.
The main part of the leaf, called the blade, looks like a triangle or a spearhead. It is cut into smaller parts multiple times. The blade is usually 3.5 to 8 centimeters (1.4 to 3.1 in) wide. The leaf's main stem, called the rachis, is dark. The leaf segments are broadly oblong or oval-shaped, about 3 to 5 millimeters (0.1 to 0.2 in) long. The leaf tissue is grayish-green and feels leathery. The most special part is the white powder, called farina, that covers the underside of the leaf. Sometimes, a little bit of this powder is on the top surface too. When the leaves dry out, their stems curl upwards.
The fern's sori (which are groups of spore-producing structures) are found along the veins of the leaf. They form a band about 0.5 to 1.5 millimeters (0.02 to 0.06 in) wide. The edges of the leaves do not curl under to protect these sori. Each sporangium (a case holding spores) holds 64 spores. These plants are diploid, meaning they have two sets of chromosomes, with a total of 54 chromosomes.
In Mexico, where it grows widely, this fern can look quite different. Its segments can be smaller (down to 2 millimeters (0.08 in) wide). The amount of white powder on the top surface can vary. The leaf stems might be zig-zag instead of straight, or dark purplish instead of black.
This fern looks a lot like A. delicatula in Mexico, but A. incana has white powder, while A. delicatula has pale yellow powder. It also looks like A. formosa, but A. formosa has no powder at all. In the United States, many A. incana ferns were once mistakenly called A. limitanea. However, A. limitanea does not have the clear joint at the base of its leaf segments where the dark color stops.
How This Fern Got Its Name
This fern was first described in 1825 by Carl Borivoj Presl. He named it Notholaena incana. The name incana means "hoary" or "grayish-white," likely referring to the white powder on the leaves.
Later, in 1859, Georg Heinrich Mettenius described the same fern and named it Gymnogramma candida. The name candida also refers to the chalk-white powder. In 1882, Karl Anton Eugen Prantl moved G. candida into the Pellaea group, calling it P. candida.
In 1987, Michael D. Windham studied these ferns more closely. He decided that the group Notholaena sect. Argyrochosma was different enough to be its own genus. So, he created the genus Argyrochosma and moved this fern into it, naming it A. incana.
Scientists have continued to study these ferns. Even though some people wondered if A. delicatula was the same as A. incana, studies have shown they are indeed separate species. A. incana belongs to a group of ferns that all have pale powder made mostly of special compounds called terpenoids.
Where the Fern Lives and Grows
You can find Argyrochosma incana in New Mexico and Arizona. From there, it spreads south through most of Mexico to Guatemala. It also has a separate population far away in the Dominican Republic. One report even mentions it in Costa Rica, though this is not commonly listed in other plant guides.
In Mexico, this fern likes to grow on rocky slopes, banks, and ledges. It often grows in shady spots or in forests, especially those with pine and oak trees. It can be found at high elevations, from 800 to 2,950 meters (2,620 to 9,680 ft) above sea level. In the United States, at the northern edge of its range, it grows only on igneous (volcanic) rock in canyon walls. In Guatemala, it grows on both shady and sunny rocks, and in cracks in rock walls and cliffs.
Protecting This Fern
The Argyrochosma incana fern is generally considered secure (G5) under the NatureServe conservation status system. This means it is not currently at high risk of disappearing. However, in Arizona, it is considered "imperiled," which means it is at risk of becoming endangered there.
See also
In Spanish: Argyrochosma incana para niños
