Pteridaceae
Encyclopedia
Pteridaceae is a large family of fern
s in the order Pteridales
. Members of the family have creeping or erect rhizome
s and are mostly terrestrial or epipetric
(growing on rock). The leaves
are almost always compound and have linear sori
that are typically on the margins of the leaves
and lack a true indusium, typically being protected by a false indusium formed from the reflexed margin of the leaf. The family includes four groups of genera that are sometimes recognized as separate families: the adiantoid, cheilanthoid, pteroid, and hemionitidoid ferns. Relationships among these groups remain unclear, and although some recent genetic analyses of the Pteridales suggest that neither the family Pteridaceae nor the major groups within it are all monophyletic
, as yet these analyses are insufficiently comprehensive and robust to provide good support for a revision of the order at the family level. As traditionally defined, the groups within Pteridaceae are as follows:
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 in the order Pteridales
Pteridales
The Pteridales are ferns that have their sori in linear strips under the edge of the leaf tissue, usually with the edge of the lamina reflexed over.This order is considered a family under the Smith classification...
. Members of the family have creeping or erect rhizome
Rhizome
In botany and dendrology, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes...
s and are mostly terrestrial or epipetric
Epipetric
An epipetric plant, is one that is found growing on rocks. Many ferns fall into this category of plant habitat, including Asplenium . Epipetric plants are called Lithophytes....
(growing on rock). The leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
are almost always compound and have linear sori
Sorus
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....
that are typically on the margins of the leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
and lack a true indusium, typically being protected by a false indusium formed from the reflexed margin of the leaf. The family includes four groups of genera that are sometimes recognized as separate families: the adiantoid, cheilanthoid, pteroid, and hemionitidoid ferns. Relationships among these groups remain unclear, and although some recent genetic analyses of the Pteridales suggest that neither the family Pteridaceae nor the major groups within it are all monophyletic
Monophyly
In common cladistic usage, a monophyletic group is a taxon which forms a clade, meaning that it contains all the descendants of the possibly hypothetical closest common ancestor of the members of the group. The term is synonymous with the uncommon term holophyly...
, as yet these analyses are insufficiently comprehensive and robust to provide good support for a revision of the order at the family level. As traditionally defined, the groups within Pteridaceae are as follows:
- Adiantoid ferns; epipetric, terrestrial or epiphyticEpiphyteAn epiphyte is a plant that grows upon another plant non-parasitically or sometimes upon some other object , derives its moisture and nutrients from the air and rain and sometimes from debris accumulating around it, and is found in the temperate zone and in the...
in moist habitats, rachis often dichotomously branching; sori relatively small and discrete with sproangiaSporangiumA sporangium is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. All plants, fungi, and many other lineages form sporangia at some point in their life cycle...
born on the false indusium rather than the leaf blade proper; only one genus:- Adiantum L. – maidenhair ferns
- Cheilanthoid ferns; primarily epipetric in semiarid habitats; leaves mostly with well-developed scales or trichomeTrichomeTrichomes are fine outgrowths or appendages on plants and certain protists. These are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae.- Algal trichomes :...
s, often bipinnate or otherwise highly compound; sporangia mostly born in marginal sori with false indusia that are +/- continuous around the leaf margins; several genera, including:- ArgyrochosmaArgyrochosmaArgyrochosma is a genus of ferns known commonly as false cloak ferns. Species now in this genus were previously treated as members of related genera Notholaena or Pellaea but were segregated into their own genus in 1987. These ferns, of which there are about 20 species, are native to the Americas,...
(J.Sm.) Windham – false cloak ferns - AspidotisAspidotisAspidotis is a small genus of leptosporangiate ferns 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...
(Nutt. ex Hook.) Copel. – lace ferns - AstrolepisAstrolepisAstrolepis is a small genus of ferns in the family Pteridaceae. It was formed in 1992 from species previously placed in Cheilanthes and Notholaena. The name is derived from the Greek words ἄστρον , meaning "star," and λεπίς , meaning "scale," referring to the star-like scales on adaxial blade...
D.M.Benham & Windham – cloak ferns - Cheilanthes Sw. – lip ferns
- NotholaenaNotholaenaNotholaena is a genus of ferns in the family Pteridaceae found exclusively in the New World. Ferns of this genus are mostly epipetric or occurring in coarse, gravelly soils, and are most abundant and diverse in the mountain ranges of warm arid or semiarid regions...
R.Br. – cloak ferns - PellaeaPellaeaPellaea is a genus of ferns in the family Pteridaceae. The name is derived from the Greek word πελλος , meaning "dark," and refers to the bluish-gray stems. Members of the genus are commonly known as cliffbrakes...
Link – cliff brakes
- Argyrochosma
- Pteridoid ferns; terrestrial and epipetric in moist habitats; leaves mostly without prominent scales or trichomes, most often pinnatePinnatePinnate is a term used to describe feather-like or multi-divided features arising from both sides of a common axis in plant or animal structures, and comes from the Latin word pinna meaning "feather", "wing", or "fin". A similar term is pectinate, which refers to a comb-like arrangement of parts...
but sometimes more compound; sporangia born in marginal sori with false indusia that are +/- continuous around the leaf margins; several genera, including:- Pteris L. – brakes
- Onychium Kaulf.
- Parkerioid ferns; aquaticAquatic plantAquatic plants are plants that have adapted to living in aquatic environments. They are also referred to as hydrophytes or aquatic macrophytes. These plants require special adaptations for living submerged in water, or at the water's surface. Aquatic plants can only grow in water or in soil that is...
in swamps and/or mangroves, including:- AcrostichumAcrostichumAcrostichum was one of the original pteridophyte genera delineated by Linnaeus. It was originally drawn very broadly, including all ferns that had sori apparently "acrostichoid", or distributed in a solid mass across the back of the frond, rather than organized in discrete sori...
L. – leather ferns - CeratopterisCeratopterisCeratopteris is the only genus among homosporous ferns that is exclusively aquatic. It is pan-tropical.-Description:Erect aquatic or subaquatic ferns of moderate size...
Brongn.
- Acrostichum
- Hemionitidoid ferns; terrestrial, epipetric or epiphytic in moist or semiarid habitats; leaves simple, pinnate, or more compound; sporangia born in linear non-marginal, exindusiate sori or sometimes in marginal sori; several genera, including:
- AnogrammaAnogrammaAnogramma is a genus of fern in the Pteridaceae family. It contains 8 putative species:* Anogramma ascensionis Diels – endemic to Ascension Island, South Atlantic Ocean.* Anogramma caespitosa – only found on Mount Kilimanjaro, Tanzania....
Link - CryptogrammaCryptogrammaCryptogramma is a genus of ferns known commonly as rockbrakes or parsley ferns. They can be found in temperate regions on several continents worldwide. These ferns have two kinds of leaves which often look so different that at first glance they appear to belong to different plants...
R.Br. – rock brakes - Eriosorus Fée
- Hemionitis L.
- JamesoniaJamesoniaEriosorus and Jamesonia are two closely related genera in the taenitoid group of the core pteridoid ferns. They have long been recognized as being closely related, and recent genetic evidence has demonstrated that they are both paraphyletic genera, but only in regards to each other...
Hook. & Grev. - Pityrogramma Link – gold ferns
- Anogramma