Myriopteris aemula

Last updated

Texas lip fern
Status TNC G4.svg
Apparently Secure  (NatureServe)
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Division: Polypodiophyta
Class: Polypodiopsida
Order: Polypodiales
Family: Pteridaceae
Genus: Myriopteris
Species:
M. aemula
Binomial name
Myriopteris aemula
(Maxon) Grusz & Windham
Synonyms
  • Cheilanthes aemulaMaxon
  • Hemionitis aemula(Maxon) Christenh.

Myriopteris aemula, the Texas lip fern or rival lip fern, is a moderately-sized fern of Texas 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 aemula until 2013, when the genus Myriopteris was again recognized as separate from Cheilanthes. It typically grows on limestone rock.

Contents

Description

Leaf bases are closely spaced along the rhizome, [1] variously described as 1 to 2 millimeters (0.04 to 0.08 in) [2] or 4 to 7 millimeters (0.2 to 0.3 in) in diameter. [1] The rhizome bears persistent scales, which are linear to narrowly lanceolate, straight or slightly twisted, and loosely appressed (pressed against the surface of the rhizome). [1] Their margins are entire (untoothed). [2] They may be uniformly brown [1] or tan to orange-brown [2] [3] in color, or be darker at their base, [1] [2] particularly in the center. [3]

The fronds spring up in clusters; [4] they do not unfold as fiddleheads like typical ferns (noncircinate vernation). When mature, they are 10 to 55 centimeters (3.9 to 22 in) long [1] [2] [4] and 4 to 15 centimeters (2 to 6 in) wide. [1] The stipe (the stalk of the leaf, below the blade) is 6 to 16 centimeters (2.4 to 6.3 in) long, [3] representing one-third to one-half of the total length of the leaf. [2] The upper surface of the stipe is rounded, and it is black to dark brown in color, [1] [4] or black to very dark purple. [2] It may be hairless, or bear a few hairs (long ones of 1 mm and short ones less than 0.1 mm) on the upper surface. [2] [3]

The leaf blades range in shape from deltate to ovate. The blade is usually tripinnate (cut into pinnae, pinnules, and pinnulets) to tripinnate-pinnatifid (with deeply lobed pinnulets) at the base, [1] [4] or even quadripinnate. [2] The rachis (leaf axis) is rounded on the upper side. It bears twisted hairs tightly pressed to it on the upper side, and scattered, spreading, straight hairs on the lower side; no scales are present. The pinnae are not jointed at the base, [1] [4] and the dark pigmentation of the rachis enters the edge of the pinnae. [1] The pinnae at the base of the leaf are slightly larger than the pinnae immediately above them [1] [4] and the pinnae are somewhat asymmetric about the costa (pinna axis). [1] The basiscopic pinnules (pointing at the leaf base) are slightly larger and more deeply dissected than the acroscopic pinnules (pointing at the leaf tip). [2] The lowest pair of basiscopic pinnules closest to the stem are noticeably larger than adjacent pinnules [1] [3] [5] and thin in texture. [2] The upper and lower surfaces of the pinnae have a few soft hairs, 0.5–0.8 mm in length or none at all. [1] [2] The costae are black on the upper side for most of their length [1] and lack scales beneath. [1] [4] The pinnulets are narrowly elliptic to elongate-deltate, [1] and not bead-shaped as in some other species of Myriopteris. [1] [4] They are cordate at the base and acute at the tip. [3] The largest pinnulets are 3 to 6 millimeters (0.12 to 0.24 in) long, [1] [4] and have sparse white hairs on upper and lower surfaces, or lack hairs entirely. [1]

On fertile fronds, the sori are protected by false indusia formed by the edge of the leaf curling back over the underside. The false indusia are slightly differentiated from the rest of the leaf tissue, and are 0.05–0.3 mm wide. [1] [2] The edges of the indusia are not toothed or lobed. [3] Beneath them, the sori are usually not continuous around the edge of the leaf, and are often concentrated on lateral lobes of the fertile pinnulets, [1] particularly at the ends of veins. [2] Each sporangium in a sorus carries 64 tan spores. Individual sporophytes are sexual diploids, with a diploid chromosome number of 2n = 58. [1] [2]

It can be confused with a number of closely related species in the "alabamensis clade" of Myriopteris. M. alabamensis and M. microphylla have slightly less divided fronds which are lanceolate and hence more narrow towards the base, while M. cucullans and M. notholaenoides also have lanceolate fronds and bear abundant golden hairs and narrow, hair-like scales on the rachis. [6]

Taxonomy

Myriopteris aemula was first described by William Ralph Maxon in 1908, as Cheilanthes aemula, based on material collected by Edward Palmer in 1907 from Ciudad Victoria. He distinguished it from Cheilanthes microphylla , found growing with it, by its greater degree of cutting and the triangular shape of the leaf blade. [7] The specific epithet aemula means "rivalling" or "emulating", [8] and is believed to refer to its "emulation" of the C. microphylla found growing with it. [4]

The development of molecular phylogenetic methods showed that the traditional circumscription of Cheilanthes, including that used by Maxon, 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. aemula, which thus became Myriopteris aemula. [9]

In 2018, Maarten J. M. Christenhusz transferred the species to Hemionitis as H. aemula, as part of a program to consolidate the cheilanthoid ferns into that genus. [10]

The common name "lip fern" comes from the position of the sporangia at the edge or lip of the leaf, typical of the genus. [11] This species is referred to as "rival lip fern", a translation of the specific epithet aemula, [4] or "Texas lip fern". [1] [3] [4]

Further molecular studies in Myriopteris demonstrated the existence of three well-supported clades within the genus. M. allosuroides belongs to what Grusz et al. informally named the alabamensis clade, and is sister to a group consisting of M. microphylla , M. moritziana , M. scabra , and M. fimbriata . [12]

Distribution and habitat

Myriopteris aemula is found in scattered locations in southern Texas, including the Trans-Pecos. [4] [13] Its range extends throughout the length of Mexico, particularly in the eastern and central states, as far south as Chiapas. [2]

The species grows on limestone bedrock, on rocky slopes and ledges, [1] [2] [4] and in cracks and openings in the rock. [3] It occurs at an altitude from 100 to 1,800 meters (330 to 5,900 ft). [1] [2]

Ecology and conservation

While globally secure (G4), M. aemula is considered by NatureServe to be vulnerable in Texas. [14]

Notes and references

Related Research Articles

<i>Myriopteris parryi</i> Species of fern

Myriopteris parryi, formerly known as Cheilanthes parryi, is a species of lip fern known by the common name Parry's lip fern.

<i>Myriopteris clevelandii</i> Species of 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.

<i>Myriopteris cooperae</i> Species of fern

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.

<i>Myriopteris gracillima</i> Species of fern

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.

<i>Myriopteris windhamii</i> Species of fern

Myriopteris windhamii, formerly known as Cheilanthes villosa, is a species of lip fern, with the common name villous lipfern. It is native to the southwestern United States.

<i>Myriopteris tomentosa</i> Species of fern

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.

<i>Myriopteris myriophylla</i> Species of fern

Myriopteris myriophylla, the Central American lace fern, is a species of lip fern. Despite its common name, this species is native as far south as Argentina. It is adapted to dry areas.

<i>Myriopteris lanosa</i> Species of fern

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.

<i>Myriopteris</i> Genus of ferns

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.

<i>Myriopteris alabamensis</i> Species of fern

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 known only from one collection in Tamaulipas, Mexico. It closely resembles Myriopteris longipila and was not described as a distinct taxon until 2004.

Myriopteris yatskievychiana is a small fern native to Mexico, a member of the family Pteridaceae. It is known only from a single collection in the Mexican state of Sonora. While superficially similar to golden lip fern, a widespread species in Mexico, differences in its coating of hairs and its small size make it distinctive. 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.

Myriopteris allosuroides is a moderately-sized fern of 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.

<i>Myriopteris aurea</i> Species of fern

Myriopteris aurea, the golden lip fern or Bonaire lip fern, is a moderately-sized fern native to the Americas, a member of the family Pteridaceae. Unlike many members of its genus, its leaf is only modestly dissected into lobed leaflets (pinnae), which are hairy both above and below. One of the cheilanthoid ferns, until 2013 it was classified in the genus Cheilanthes as Cheilanthes bonariensis, when the genus Myriopteris was again recognized as separate from Cheilanthes. It typically grows on dry, rocky slopes, and ranges from Mexico, where it is common and widespread, and the southwestern United States south and east through Central and South America as far as Chile and Argentina.

Argyrochosma lumholtzii is a rare fern in the family Pteridaceae known from Sonora, Mexico. It is quite similar to Jones' false cloak fern, but has black leaf axes and a less highly divided leaf. First described as a species in 1939, honoring the explorer Carl Sofus Lumholtz, it was transferred to the new genus Argyrochosma in 1987, recognizing their distinctness from the "cloak ferns".

<i>Argyrochosma microphylla</i> Species of fern in the family Pteridaceae

Argyrochosma microphylla, the small-leaf false cloak fern, is a species of fern native to New Mexico, Texas and northern Mexico. It grows on limestone rocks and cliffs, and has finely-divided leaves with small leaf segments, often folded in half when dry, which lack the white powder present on the leaf underside of many related species. First described as a species in 1869, it was transferred to the new genus Argyrochosma in 1987, recognizing their distinctness from the "cloak ferns".

<i>Myriopteris rufa</i> Species of fern

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.

<i>Myriopteris rawsonii</i> Species of fern

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.

<i>Myriopteris scabra</i> Species of plant

Myriopteris scabra, commonly known as rough lipfern, is a species of cheilanthoid fern native to Mexico and the south-western United States (Texas).

Myriopteris chipinquensis is a fern endemic to Mexico, a member of the family Pteridaceae. One of the cheilanthoid ferns, it was classified in the genus Cheilanthes until 2013, when the genus Myriopteris was again recognized as separate from Cheilanthes. It grows in oak-pine forests of the Sierra Madre Oriental, often with the very similar and closely related Myriopteris tomentosa.

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 Windham & Rabe 1993.
  2. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Mickel & Smith 2004, p. 180.
  3. 1 2 3 4 5 6 7 8 9 Lellinger 1985, p. 139.
  4. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Diggs & Lipscomb 2014, p. 232.
  5. ↑ Diggs & Lipscomb 2014, p. 231.
  6. ↑ Mickel & Smith 2004, pp. 180–181.
  7. ↑ Maxon 1908, p. 495.
  8. ↑ Short & George 2013, p. 116.
  9. ↑ Grusz & Windham 2013.
  10. ↑ Christenhusz, Fay & Byng 2018, p. 9.
  11. ↑ Diggs & Lipscomb 2014, p. 230.
  12. ↑ Grusz et al. 2014, p. 704.
  13. ↑ Kartesz 2014.
  14. ↑ NatureServe 2022.

Works cited

  • Christenhusz, Maarten J. M.; Fay, Michael F.; Byng, James W. (2018). Plant Gateway's the Global Flora: A practical flora to vascular plant species of the world. Vol. 4. ISBN   978-0-9929993-9-1.
  • Diggs, George M. Jr.; Lipscomb, Barney L. (2014). The Ferns and Lycophytes of Texas. Fort Worth, Texas: Botanical Research Institute of Texas Press. ISBN   978-1-889878-37-9.
  • Grusz, Amanda L.; Windham, Michael D. (2013). "Toward a monophyletic Cheilanthes: The resurrection and recircumscription of Myriopteris (Pteridaceae)". PhytoKeys (32): 49–64. doi: 10.3897/phytokeys.32.6733 . PMC   3881352 . PMID   24399906.
  • Grusz, Amanda L.; Windham, Michael D.; Yatskievych, George; Huiet, Lane; Gastony, Gerald J.; Pryer, Kathleen M. (2014). "Patterns of Diversification in the Xeric-adapted Fern Genus Myriopteris (Pteridaceae)". Systematic Botany. 39 (3): 698–714. doi:10.1600/036364414X681518. JSTOR   24546228. PMC   4651630 . PMID   26649266.
  • Kartesz, John T. (2014). "Myriopteris". Biota of North America Program.
  • Lellinger, David B. (1985). A Field Manual of the Ferns & Fern-Allies of the United States & Canada . Washington, DC: Smithsonian Institution Press. ISBN   0-87474-603-5.
  • Maxon, William R. (1908). "Studies of Tropical American Ferns-No. 1". Contributions from the United States National Herbarium. 10 (7).
  • Mickel, John T.; Smith, Alan R. (2004). The Pteridophytes of Mexico. Memoirs of the New York Botanical Garden. Vol. 88. Bronx, New York: New York Botanical Garden. ISBN   978-0-89327-488-7.
  • "Cheilanthes aemula". NatureServe. October 1, 2022. Retrieved October 3, 2022.
  • Short, Emma; George, Alex (2013). A Primer of Botanical Latin with Vocabulary. Cambridge, England: Cambridge University Press. ISBN   978-1-107-69375-3.
  • Windham, Michael D.; Rabe, Eric W. (1993). "Cheilanthes aemula". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico. Vol. 2: Pteridophytes and Gymnosperms. New York and Oxford: Oxford University Press. Retrieved January 30, 2019.
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