Myriopteris gracillima | |
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Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Division: | Polypodiophyta |
Class: | Polypodiopsida |
Order: | Polypodiales |
Family: | Pteridaceae |
Subfamily: | Cheilanthoideae |
Genus: | Myriopteris |
Species: | M. gracillima |
Binomial name | |
Myriopteris gracillima | |
Synonyms | |
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Myriopteris gracillima, formerly known as Cheilanthes gracillima, is a species of lip fern known by the common name lace lip fern. It is native to western North America, where it grows in rocky habitat from British Columbia to California to Montana. [2] [3]
Myriopteris gracillima is a small fern with dark green leaves up to about 25 cm (10 in) long that arise from a short creeping ground stem (rhizome), such that plants often have an elongated base, for example creeping along a rock crevice. Each frond is intricately divided into segments made up of pairs of smaller segments which are oval in shape and oblong beadlike, with their edges rolled under, giving it a somewhat succulent appearance. They are also quite hairy and scaly, mostly on the underside of the leaf and leaf mid-rib. The sori are located within rolled-under margins (false indusium) of each tiny leaf segment. It usually grows in sun in crevices in rock formations or sometimes in thin soil in and around rocks. [2]
More technical description adapted from Burke Herbarium: [4] Myriopteris gracillima is a lithophytic perennial, with leaves emerging from short creeping stems that are 4–8 mm (0.2–0.3 in) in diameter with narrow scales that are uniformly brown or with a weakly defined dark central stripe; the scales are straight to somewhat contorted, loosely appressed, and persistent. Leaves are 5–25 cm (2–10 in) long and 1–2.5 cm (0.4–1 in) wide and are born on a dark brown petiole. The leaf blade is linear-oblong and 2-3-pinnate at base. The rachis is rounded on the upper surface, with dispersed linear scales. Pinnae are not articulate, and the dark stalk color continues into the pinna base. Pinnae are usually equilateral, appearing slightly pubescent or glabrous on upper surface, with pinna midribs green on upper surface for the majority of length. Scales on the underside of the rachis are arranged in several rows, linear and truncate at base, inconspicuous, 0.1–0.4 mm (0.004–0.02 in) wide at most, loosely imbricate, not hiding the ultimate segments, and long-ciliate with cilia typically confined to the base. The ultimate pinna segments are oblong or rarely ovate and beadlike, 1.5–3 mm (0.06–0.1 in) at most. The leaf lower surface is densely covered with branched hairs and small ciliate scales. The leaf upper surface has dispersed and branched hairs, which tend to be shed as the leaf ages. [4]
M. gracillima is native to mountains in western North America, ranging from British Columbia to California. It is absent in lower elevation dry inland areas such as the shrub-steppe of central Washington and Oregon and the central valley of California, but is present in the Rocky Mountains in British Columbia, Idaho, western Montana, and Nevada. It is also found at low elevation in the Columbia River gorge only in the region where it transects the Cascade Mountain range, [4] [2] presumably because of higher precipitation.
M. gracillima grows primarily in sunny exposures in rock crevices with little or no soil. [4] [2]
Like many cheilanthoid ferns, M. gracillima tolerates desiccation well. During an extended dry period leaves curl and expose their hairy abaxial (lower) surface, presumably to reduce water loss. The leaves uncurl and green up when moisture returns.
Myriopteris gracillima was first described by Daniel Cady Eaton in 1859, as Cheilanthes gracillima, based on material collected in the Cascade Range of Oregon. [5] The specific epithet gracillima, meaning "very slender", [6] presumably refers to the linear scales on the leaf axes, which Eaton described with that word. [5] By a strict application of the principle of priority, Oliver Atkins Farwell transferred the species to the genus Allosorus as Allosorus gracillimus in 1931, that genus having been published before Cheilanthes . [7] Farwell's name was rendered unnecessary when Cheilanthes was conserved over Allosorus in the Paris Code published in 1956.
The development of molecular phylogenetic methods showed that the traditional circumscription of Cheilanthes is polyphyletic. Convergent evolution in arid environments is thought to be responsible for widespread homoplasy in the morphological characters traditionally used to classify it and the segregate genera that have sometimes been recognized. On the basis of molecular evidence, Amanda Grusz and Michael D. Windham revived the genus Myriopteris in 2013 for a group of species formerly placed in Cheilanthes. One of these was C. gracilliima, which thus became Myriopteris gracillima. [8] In 2018, Maarten J. M. Christenhusz transferred the species to Hemionitis as H. gracillima, as part of a program to consolidate the cheilanthoid ferns into that genus. [9]
Myriopteris gracillima (maternal) and Myriopteris covillei (paternal) are the parents of the allotetraploid fertile hybrid Myriopteris intertexta . [10] [8] [11]
Myriopteris covillei, formerly known as Cheilanthes covillei, is a species of cheilanthoid fern known by the common name Coville's lip fern. Coville's lip fern is native to the southwestern United States and Mexico.
Myriopteris parryi, formerly known as Cheilanthes parryi, is a species of lip fern known by the common name Parry's lip fern.
Myriopteris clevelandii, formerly known as Cheilanthes clevelandii, is a species of lip fern known by the common name Cleveland's lip fern. It is native to southern California and Baja California in Mexico. The leaf is divided into small, bead-like segments densely covered with scales beneath. In M. clevelandii, some of these scales are reduced to hairlike structures, which help distinguish it from the closely related M. covillei. It is usually found growing on exposed rock, particularly igneous rock.
Myriopteris cooperae, formerly Cheilanthes cooperae, is a species of lip fern known by the common name Mrs. Cooper's lip fern, or simply Cooper's lip fern. Its leaves grow in clusters and are highly dissected into oblong segments, rather than the beadlike segments found in some other members of the genus. The axes of the leaves are dark and covered in long, flattened hairs. It is endemic to California, where it grows in rocky habitats, usually over limestone. The species was named in honor of its collector, Sarah Paxson Cooper; according to Daniel Cady Eaton, who described it in 1875, it was the first fern species to be named for a female botanist.
Myriopteris intertexta, formerly Cheilanthes intertexta, is a species of lip fern known by the common name coastal lip fern. It is native to montane California and western Nevada, Oregon east of the Cascades, and with a disjunct population in central Utah. It grows in dry rocky habitats in sun, typically in rock cracks with little or no soil.
Myriopteris newberryi, formerly Cheilanthes newberryi, is a species of lip fern known by the common name Newberry's lip fern. It is native to southern California and Baja California.
Myriopteris tomentosa, formerly known as Cheilanthes tomentosa, is a perennial fern known as woolly lipfern. Woolly lipfern is native to the southern United States, from Virginia to Arizona and Georgia, and Mexico.
Myriopteris lanosa, the hairy lip fern, is a moderately-sized fern of the eastern United States, a member of the family Pteridaceae. Its leaves and stem are sparsely covered in hairs, but lack scales, hence its common name. One of the cheilanthoid ferns, it was usually classified in the genus Cheilanthes until 2013, when the genus Myriopteris was again recognized as separate from Cheilanthes. It typically grows in shallow, dry, soil, often in rocky habitats.
Myriopteris, commonly known as the lip ferns, is a genus of cheilanthoid ferns. Like other cheilanthoids, they are ferns of dry habitats, reproducing both sexually and apogamously. Many species have leaves divided into a large number of small, bead-like segments, the probable inspiration for the generic name. Hairs and/or scales are often present on both the upper and lower surfaces of the leaf, and their presence and appearance are useful in distinguishing between species. The genus is most diverse in Mexico, but species are found from southwestern Canada south to southern Chile, and one species is endemic to southern Africa.
Myriopteris alabamensis, the Alabama lip fern, is a moderately-sized fern of the United States and Mexico, a member of the family Pteridaceae. Unlike many members of its genus, its leaves have a few hairs on upper and lower surfaces, or lack them entirely. One of the cheilanthoid ferns, it was usually classified in the genus Cheilanthes as Cheilanthes alabamensis until 2013, when the genus Myriopteris was again recognized as separate from Cheilanthes. It typically grows in shade on limestone outcrops.
Myriopteris maxoniana is a species of cheilanthoid fern endemic to the Mexican state of Tamaulipas. It is known only from one collection. It closely resembles Myriopteris longipila and was not described as a distinct taxon until 2004.
Myriopteris allosuroides is a moderately-sized fern endemic to Mexico, a member of the family Pteridaceae. Unlike many members of its genus, its rachides are grooved on the upper surface and largely free of hairs or scales. One of the cheilanthoid ferns, it was usually classified in the genera Cheilanthes or Pellaea until 2013, when the genus Myriopteris was again recognized as separate from Cheilanthes. It typically grows on dry, rocky slopes over acidic, particularly basaltic, rock.
Myriopteris rufa, commonly known as Eaton's lip fern, is a moderately-sized fern of Mexico and the southwestern United States, with outlying populations in Costa Rica and the Appalachian Mountains. One of the cheilanthoid ferns, it was usually classified in the genus Cheilanthes, as Cheilanthes eatonii, until 2013, when the genus Myriopteris was again recognized as separate from Cheilanthes. It typically grows in rocky habitats, most frequently on limestone but also sometimes on basalt or shale.
Myriopteris rawsonii, formerly known as Cheilanthes rawsonii, is a perennial fern native to Namaqualand in Southern Africa. Like many other cheilanthoid ferns, it is adapted to dry conditions, bearing a thick layer of pale hairs on the underside of its pinnate-pinnatifid leaves. It is the only African representative of its clade of cheilanthoids, the otherwise American genus Myriopteris. It spends much of the year in a dried-out, dormant state, rehydrating and putting out new growth during winter rains. Its name honors the botanist and civil servant Sir Rawson W. Rawson.
Myriopteris wootonii, formerly known as Cheilanthes wootonii, is a species of fern in the Pteridaceae family with the common name Wooton's lace fern.
Myriopteris fendleri, formerly known as Cheilanthes fendleri, is a species of fern in the Pteridaceae family with the common name Fendler's lip fern. It is native to the southwest United States and northern Mexico.
Myriopteris lindheimeri, formerly known as Cheilanthes lindheimeri, is a species of fern in the Pteridaceae family with the common name fairy swords.
Myriopteris scabra, commonly known as rough lipfern, is a species of cheilanthoid fern native to Mexico and the south-western United States (Texas).
Myriopteris cinnamomea is a Central American fern. It is very similar to M. mickelii of southern Mexico and to other species in the "alabamensis clade" of Myriopteris. It is modestly sized, with leaves not more than 30 centimeters (12 in) long. They are divided into pinnae, which in turn are divided into lobed pinnules, and covered with pale brown hairs on the underside.
Myriopteris mickelii is a fern endemic to southern Mexico. It is very similar to M. cinnamomea of Central America, from which it was separated when described in 1980, and to other species in the "alabamensis clade" of Myriopteris. Named after the pteridologist John T. Mickel, it grows on dry, lightly shaded slopes and banks.