''Myriopteris covillei'', formerly known as ''Cheilanthes covillei'', is a species of

cheilanthoid Cheilanthoideae is one of the five subfamilies of the fern family Pteridaceae. The subfamily is thought to be monophyletic, but some of the genera into which it has been divided are not, and the taxonomic status of many of its genera and species ...

fern known by the common name Coville's lip fern. Coville's lip fern is native to the southwestern United States and Mexico.

Description

Leaf bases are closely spaced along the

rhizome In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...

, which is typically in diameter. It is covered with persistent scales about long, which are linear to narrowly lanceolate, straight or slightly twisted, and tightly appressed (pressed against the surface of the rhizome). They are a uniform dark brown to black in color, or in some cases have paler, narrow margins of a light brown color, and lack marginal teeth. The fronds spring up in clusters; they do not unfold as

fiddlehead Fiddleheads or fiddlehead greens are the furled fronds of a young fern, harvested for use as a vegetable. Left on the plant, each fiddlehead would unroll into a new frond (circinate vernation). As fiddleheads are harvested early in the sea ...

s like typical ferns (noncircinate vernation). When mature, they are long. The stipe (the stalk of the leaf below the blade) is long and less than wide, rounded on the upper surface, dark brown to dark reddish-brown in color. It is covered with white to red-brown, lanceolate to linear scales. The leaf blades are lanceolate to

ovate Ovate may refer to: *Ovate (egg-shaped) leaves, tepals, or other botanical parts *Ovate, a type of prehistoric stone hand axe *Ovates, one of three ranks of membership in the Welsh Gorsedd *Vates In modern English, the nouns vates () and ovat ...

- deltate in shape, typically or even wide and tripinnate to tetrapinnate (cut into pinnae, pinnules, pinnulets, and sometimes into divisions of pinnulets) at the base. The rachis (leaf axis) is rounded, rather than grooved, on its upper surface, dark in color, with some scales but no hairs. No distinct joint is present where the pinnae attach to the rachis, the dark color of the latter continuing into the base of the costa (pinna axis). Each pinna is equilateral in shape, and the lowest pair of pinnae is not significantly enlarged compared to the others. Aside from the dark base, the upper surface of the costae is green along much of their length. The lower surface of the costae is covered in conspicuous scales. These are ovate-lanceolate in shape, and deeply

cordate Cordate is an adjective meaning 'heart-shaped' and is most typically used for: * Cordate (leaf shape), in plants * Cordate axe, a prehistoric stone tool See also * Chordate A chordate () is an animal of the phylum Chordata (). All chordat ...

(notched at the base to appear heart-shaped). The largest scales are wide. The scales overlap each other, and sometimes conceal the final subdivisions of the leaf from below. Only the basal lobes of the scales are ciliate. This fern has dark to medium green leaves (fronds) which may be up to 4-pinnate (made up of leaflets that subdivide up to 3 times), such that the leaflets are layered with overlapping rounded segments. The leaves as a whole have a bumpy, cobbled look when viewed from above. The edges of the leaflets are curled under (forming a false

indusium A sorus (pl. sori) is a cluster of sporangia (structures producing and containing spores) in ferns and fungi. A coenosorus (plural coenosori) is a compound sorus composed of multiple, fused sori. Etymology This New Latin word is from Ancient ...

) and their undersides have wide scales which are lengthened outgrowths of the

epidermis The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and hypodermis. The epidermis layer provides a barrier to infection from environmental pathogens and regulates the amount of water rele ...

. Tucked under the scales and false indusium are the sporangia, which make the spores. ''Myriopteris covillei'' can be distinguished from its very similar relative '' Myriopteris intertexta'' by the scales on the underside of the leaflets. These scales are up to 3 mm wide at their base in ''M. covillei'', giving them an elongated triangular papery appearance, whereas those of '' M. intertexta'' are 1 mm wide, appearing more like a flattened thread. Myriopteris covillei iNat-188350631

Range and Habitat

Coville's lip fern is native to California, Baja California, Arizona, Oregon, and Utah. It grows in rocky crevices in the mountains and foothills. In California it is found in

chaparral Chaparral ( ) is a shrubland plant community and geographical feature found primarily in the U.S. state of California, in southern Oregon, and in the northern portion of the Baja California Peninsula in Mexico. It is shaped by a Mediterranean c ...

yellow pine forest Ponderosa pine forest is a plant association and plant community dominated by ponderosa pine and found in western North America. It is found from the Rocky Mountains to the Pacific Coast Ranges in the Western United States and Western Canada. In ...

, pinyon-juniper woodland, and Joshua tree woodland habitats.

Taxonomy

Based on plastid DNA sequence, ''Myriopteris covillei'' is part of ''Myriopteris'' clade C (''covillei'' clade) and is most closely related to ''Myriopteris clevelandii'' and ''Myriopteris gracillima''. In addition, ''Myriopteris covillei'' is one of the parents of the fertile allotetraploid '' Myriopteris intertexta''.Grusz, A. L., M. D. Windham, and K. M. Pryer. 2009. Deciphering the origins of apomictic polyploids in the Cheilanthes yavapensis complex (Pteridaceae). American Journal of Botany 96: 1636–1645

Ecology and conservation

While globally apprently secure (G4), ''M. covillei'' is threatened in the northern part of its range. NatureServe considers it to be critically imperiled in Oregon, imperiled in Utah, and vulnerable in Nevada.

References

Works cited

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External links

Jepson Manual eFlora (TJM2) treatment of ''Myriopteris covillei''
— formerly ''Cheilanthes covillei''.
UC Photos gallery — ''Cheilanthes covillei''
{{Taxonbar, from=Q15586043 covillei Ferns of California Ferns of Mexico Ferns of the United States Flora of Arizona Flora of Baja California Flora of Oregon Flora of Utah Flora of the California desert regions Flora of the Sierra Nevada (United States) Natural history of the California chaparral and woodlands Natural history of the Mojave Desert Natural history of the Peninsular Ranges Natural history of the Santa Monica Mountains Natural history of the Transverse Ranges Plants described in 1918