Aspidotis
Encyclopedia
Aspidotis is a small genus of leptosporangiate
fern
s known commonly as laceferns. Most species are native to slopes, ridges, and rocky outcroppings, primarily in California and Mexico, although one species included in the genus by some authorities is widely distributed in eastern Africa.
.
of Hypolepis
, then to Cheilanthes. David Lellinger
established Aspidotis as a distinct genus based on characteristic features of its false indusia and its leaves, including their shiny surface, although as late as the 1990 publication of the Kubitzki system
, these ferns were sometimes still included in Cheilanthes.
Currently, as many as five species are recognized, including one identified as a fertile interspecific hybrid.
However, some authorities retain one or more of these species in other genera, excluding A. meifolia, A. schimperi, or both.
Other species of plants commonly known as laceferns are not part of Aspidotis and are often not closely related. Microlepia strigosa is from a different order
of ferns, and Asparagus setaceus
is not a fern at all.
, to higher-elevation ridges, to marginal habitats like rocky crevices and the bases of boulders.
Some laceferns show an affinity for serpentine soil
. In particular, disjunct populations
of A. densa in eastern North America are edaphic endemics
. A. carlotta-halliae and the West Coast populations of A. densa are commonly associated with these ultramafic soils but are not restricted to them.
, and refers to the distinctive shield-like false indusium found especially in A. californica. Some authors suggest ασπιδοτες (shield-bearer) as the intended origin, while others claim ασπιδος-ωτος (sheild-eared).
Leptosporangiate fern
Leptosporangiate ferns are the largest group of living ferns. They are often considered to be the class Pteridopsida or Polypodiopsida, although other classifications assign them a different rank...
fern
Fern
A fern is any one of a group of about 12,000 species of plants belonging to the botanical group known as Pteridophyta. Unlike mosses, they have xylem and phloem . They have stems, leaves, and roots like other vascular plants...
s known commonly as laceferns. Most species are native to slopes, ridges, and rocky outcroppings, primarily in California and Mexico, although one species included in the genus by some authorities is widely distributed in eastern Africa.
Description
Members of Aspidotis are small ferns, with shiny, tufted fronds generally less than 35 centimeters long (although A. schimperi may be larger). Fertile leaves have false indusia formed by the leaves' inrolled margins, which partially conceal the spore-bearing soriSorus
A sorus is a cluster of sporangia .In fungi and lichens, the sorus is surrounded by an external layer. In some red algae it may take the form of a depression into the thallus....
.
Taxonomy
The taxonomy of laceferns has been considerably refined since they were first described in the late 1800s. Species currently placed in Aspidotis were originally assigned to a sectionSection (botany)
In botany, a section is a taxonomic rank below the genus, but above the species. The subgenus, if present, is higher than the section, and the rank of series, if present, is below the section. Sections are typically used to help organise very large genera, which may have hundreds of species...
of Hypolepis
Hypolepis
Hypolepis is a genus of moth in the family Geometridae. It is considered a synonym of Psaliodes....
, then to Cheilanthes. David Lellinger
David B. Lellinger
David Bruce Lellinger is an American botanist, specializing in ferns, working at the Smithsonian Institution in Washington, DC. He began work as a student assistant in 1960 and 1961. He was hired as full-time staff in 1963. He has for some years been the curator of pteridology at the...
established Aspidotis as a distinct genus based on characteristic features of its false indusia and its leaves, including their shiny surface, although as late as the 1990 publication of the Kubitzki system
Kubitzki system
A system of plant taxonomy, the Kubitzki system is the product of an ongoing survey of vascular plants, entitled The Families and Genera of Vascular Plants....
, these ferns were sometimes still included in Cheilanthes.
Currently, as many as five species are recognized, including one identified as a fertile interspecific hybrid.
- Aspidotis californicaAspidotis californicaAspidotis californica is a species of fern known by the common name California lacefern. It is native to California and Baja California....
(California lacefern) - Aspidotis carlotta-halliaeAspidotis carlotta-halliaeAspidotis carlotta-halliae is a species of fern known by the common names tufted lacefern and Carlotta Hall's lace fern. It is endemic to California, where it is found in the Central Coast Ranges and coastal hillsides, often on serpentine soils...
(Carlotta Hall's lacefern or tufted lacefern), a fertile hybrid of A. californica and A. densa, endemic to California. - Aspidotis densaAspidotis densaAspidotis densa is a species of fern known by the common name Indian's dream. It is native to western North America from British Columbia to California to Wyoming, as well as parts of eastern North America including Quebec....
(cliffbrake or Indian's dream) - Aspidotis meifolia, endemic to Mexico.
- Aspidotis schimperi, the African species.
However, some authorities retain one or more of these species in other genera, excluding A. meifolia, A. schimperi, or both.
Other species of plants commonly known as laceferns are not part of Aspidotis and are often not closely related. Microlepia strigosa is from a different order
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
of ferns, and Asparagus setaceus
Asparagus setaceus
Asparagus setaceus, commonly known as Common Asparagus Fern, Lace Fern, Climbing Asparagus, or Ferny Asparagus, is a vine plant in the genus Asparagus. Despite its common name, the plant is not a true fern, but has leaves that resemble one.It is native to Southern Africa, and is grown elsewhere as...
is not a fern at all.
Ecology
Ferns in this genus grow in a variety of conditions, from low woodland slopes, to chaparralChaparral
Chaparral is a shrubland or heathland plant community found primarily in the U.S. state of California and in the northern portion of the Baja California peninsula, Mexico...
, to higher-elevation ridges, to marginal habitats like rocky crevices and the bases of boulders.
Some laceferns show an affinity for serpentine soil
Serpentine soil
A serpentine soil is derived from ultramafic rocks, in particular serpentinite, a rock formed by the hydration and metamorphic transformation of ultramafic rock from the Earth's mantle....
. In particular, disjunct populations
Disjunct distribution
In biology, a taxon with a disjunct distribution is one that has two or more groups that are related but widely separated from each other geographically...
of A. densa in eastern North America are edaphic endemics
Edaphic
Edaphic is a nature related to soil. Edaphic qualities may characterize the soil itself, including drainage, texture, or chemical properties such as pH. Edaphic may also characterize organisms, such as plant communities, where it specifies their relationships with soil...
. A. carlotta-halliae and the West Coast populations of A. densa are commonly associated with these ultramafic soils but are not restricted to them.
Etymology
Not all authorities agree on the exact etymology of Aspidotis. In all cases, the name is derived from GreekGreek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
, and refers to the distinctive shield-like false indusium found especially in A. californica. Some authors suggest ασπιδοτες (shield-bearer) as the intended origin, while others claim ασπιδος-ωτος (sheild-eared).