Athyrium is a genus of 180 species of terrestrial ferns, so strictly speaking is not a wildflower because it produces no blooms. It is native to moist woodland and forest in temperate and tropical regions around the world. Growing from a rhizome, the plants may be 6″ to 6′ tall and most have deciduous, feather, finely divided foliage. The fronds (=leaves) may be pinnate, three-pinnate, or pinnatifid and the stips (=stems) are often hairy or scaly at the base and may be grooved or smooth. Instead of producing seeds in fruit like flowering plants, ferns produce spores in sori (singular, sorus). The sori are located on the underside of the fronds, are usually linear or curved and are usually covered by a covering called an indusium, that is often curved or J-shaped.
Athyriums like shade or filtered light and moist, fertile, neutral to acidic soil. Propagation is by spores or division in spring.
The genus name, Athyrium, is from the Greek ἀ- (a-), meaning without, and the Greek word θύριον (thýrion) meaning little door, in references the plant’s indusium. The indusium of most ferns acts like a little door over the spore cases, but in Athyrium it is either absent or not shaped like a door, so the specific epithet is a misnomer.
Photo Credit: NC State Extension
The environmental conditions of the Southwest have resulted in at least two species of lady fern native there but they are native to other regions of the US too. The lady ferns described here are native to at least two of the states in the Southwest.
Southern Lady Fern (Athyrium asplenioides)
Broad, lacy fronds form whorled clumps that are 2-3′ tall and wide. The fronds may have reddish stipes (stems), are two to three pinnate or pinnatifid, light green, with the broadest part just above the base. The sori are either short and straight or long and recurved. An indusium covers spores that are dark brown when mature. An excellent choice for a ground cover for a woodland garden, along a stream bank, or at the edge of a shaded pond.
Alternate Names: None
Native Range: Oklahoma and Texas as well as places in the Midwest, Southeast, Mid-Atlantic, and New England
Habitat: Moist to wet forests, meadows, open thickets, occasionally swamps
Type: Deciduous perennial
Height: 2-3′
Bloom Time: NA
Bloom Color: NA
Light: Dappled shade to part or full shade
Soil: Humusy, consistently moist to wet; tolerates drier soils than other lady ferns
USDA Hardiness Zones: 5-9
Photo Credit: NC State Extension
Western Lady Fern (Athyrium cyclosonum)
Considered by some experts to be a variety of east coast lady fern, western lady fern is typically larger and lighter in color. The fronds are 2-3 times pinnately compound and grow in loose vase-like tufts. The sori with their indusia are elongated and curved in a horse-shoe shape.
Alternate Names: None
Native Range: Arizona and New Mexico as well as places in the Pacific Coast, Rocky Mountain area, and Midwest.
Habitat: Swamps, streambanks, thickets, and moist woodlands and meadows
Type: Deciduous perennial
Height: 1- 6′
Bloom Time: NA
Bloom Color: NA
Light: Shade
Soil: Average, consistently moist
USDA Hardiness Zones: 3-8 (?)
Photo Credit: inaturalist
For the purpose of this article, the Southwest includes the states of Texas, Oklahoma, New Mexico and Arizona. Other states often associated with the Southwest are included in other geographic areas. The key factor linking these four states is aridity. The area includes high dry plains and true deserts as well as spurs of the Rocky Mountains. Only Texas has a coast on the ocean which brings more precipitation and humidity to east Texas and Oklahoma than elsewhere in the area. In addition to the ocean, the Rio Grande and Colorado Rivers are significant water features in the area. Although temperatures in the mountains can be cool, most of the area experiences hot temperatures for a long period each year.