CLASS CLADOXYLIDOPSIDA+

• ORDER CLADOXYLALES
  • These plants are extinct. They have 2 types of leaf-like appendages (microphylls). The sterile appendages are small and have open branching. The blade-like fertile appendages are flattened and dichotomously branched, each fertile branch terminates in a small sporangium.
  • Cladoxylon

• ORDER PSEUDOSPOROCHNALES
  • These plants are extinct with a fossil history which ranges through the Devonian. They are very large with a growth habit which resembles a tree fern. The branches resemble large fronds with sterile and fertile dichotomously branched appendages. The fertile appendages are not flattened.
  • Pseudosporochnus

• ORDER CALAMOPHYTALES
  • These plants are extinct and known from the middle Devonian. The plants show strong monopodial growth with dichotomizing ultimate branches. The microphylls are round in cross section and spirally arranged on the stems. Sporangia occur on clusters of recurved stems (these structures resemble sporangiophores (text with tooltip) Sporangiophores are fertile appendages that do not look leaf-like. The sporangiophores of the horsetails may be compound structures. ).
  • Calamophyton

CLASS COENOPTERIDOPSIDA+

• ORDER STAUROPTERIDALES
  • These plants are extinct with a fossil history through the Carboniferous. The axes have alternating pairs of frond-like branches emerging at the nodes. Elongate sporangia occur on some of the ultimate branches. The sporangia dehisce by an opening at the apex of the sporangium.
  • Stauropteris

• ORDER BOTRYOPTERIDALES
  • These plants, represented by a single genus, are extinct and known through the Carboniferous into the Permian. Stems are protostelic and fronds with vascular traces (the region of xylem is curved in x-section of the leaf trace). They grow as a trichotomizing axis which forms a bushy plant. Some fronds with large grape-like clusters of sporangia.
  • Botryopteris, Tubicaulis.

• ORDER RHACOPHYTONALES
  • These plants are extinct with a fossil history which ranges through the Carboniferous. These plants have a slender stem and large frond-like appendages. They were probably creeping. The sterile fronds have primary pinnae in 2 ranks, each of which has small, dichotomously branching stems around the pinna. The fertile fronds are more complex; some primary pinnae are sterile, the fertile primary pinnae bear ball-like dichotomously branched appendages, each of which terminates in elongate sporangia.
  • Rhacophyton, Protocephalopteris, Protopteridophyton

• ORDER ZYGOPTERIDALES
  • These plants are extinct and known from the upper Devonian to the Permian. The plants are creeping or rhizomatous. The rhizomes are covered with frond-like dichotomizing branches which occur in two ranks. The stele is H-shaped in mature stems and shows evidence of secondary growth. The sporangia are at the tips or on the abaxial surface of the ultimate branches.
  • Zygopteris, Clepsydropsis, Etapteris, Metaclepsydropsis, Ankyropteris

CLASS PSILOTOPSIDA

• ORDER OPHIOGLOSSALES
  • The plants have a short, vertical underground stem from which emerges a single leaf each year. The stem usually is an ectophloic siphonostele which exhibits lateral growth. The leaf is heteromorphic with clusters of homosporous (text with tooltip) Homosporous (adj) plants produce one type of spore. eusporangia (text with tooltip) A eusporangium is the most common spore-bearing structure in plants. Eusporangia develop from more than one cell and usually have a wall of several cell layers. Contrast a eusporangium with a leptosporangium. on a fertile pinna (text with tooltip) A fertile pinna is a segment of a compound leaf that bears sporangia. . The leaf is not circinate. The gametophyte may be saprophytic.
  • Family Ophioglossaceae: Botrychium, Helminthostachys, Mankyua, Ophioglossum, Cheiroglossa

• ORDER PSILOTALES
  • Family Psilotaceae: Psilotum, Tmesipteris

CLASS EQUISETOPSIDA [SPHENOPSIDA]

• ORDER HYENIALES+
  • These plants are found in the upper Devonian and demonstrate clear affinities with the ferns and the trimerophytes. They had heavy horizontal rhizomes from which arose branched upright axes that terminated in small branches with leafy structures. The leafy branches also had fertile zones on which sporangia were attached in a form similar to a sporangiophore. The leaves and branches were not in whorls like the typical sphenophyte.
  • Hyenia

• ORDER EQUISETALES
  • These plants are represented by a single extant genus, Equisetum. Fossil history of this group goes back to the late Paleozoic. They are primarily distinguished from the Calamitales by the reduction in branching and loss of secondary growth.
  • Family Equisetaceae: Equisetum, Equisetites+, Phyllotheca+

• ORDER CALAMITALES+
  • These plants are extinct with a fossil history which ranges from the upper Devonian to the Permian. These plants are very large and tree-like with considerable secondary growth. Some are heterosporous.
  • Calamites, Calamostachys, Calamocarpon, Annularia, Asterophyllites, Asteromyelon.

• ORDER PSEUDOBORNIALES+
  • These plants are extinct and known from the upper Devonian. The plants are large (up to 20m tall) with articulating stems. The dichotomizing branches are up to 3m long.
  • Pseudobornia

• ORDER SPHENOPHYLLALES+
  • These plants are extinct with a fossil history from the lower Devonian through the Permian or early Triassic periods. The stems have a solid core and appear triangular in cross section. The whorled leaves are wedge-shaped with dichotomizing veins. The stems are prostrate.
  • Sphenophyllum, Bowmanites

CLASS MARATTOPSIDA

These plants are often very large and tree-like (thus the name tree ferns) and typically occur in the tropics. They have a fossil history which goes back to the Carboniferous. The stems are supported by persistent leaf bases and exhibit lateral growth by a polycyclic dictyostele (text with tooltip) A dictyostele is amphiphloic siphonostele that is separated into segments in the stem cortex. . The fleshy stems and roots often have mucilage chambers in a thick cortex (text with tooltip) Cortex is a tissue of parenchymal cells that surrounds vascular tissue. . The leaves are very large, often more than 2 m long, and contain large eusporangia (some fused in synangia (text with tooltip) A Synangium is a structure made of two or more eusporangia fused together. ) on their abaxial surface. The gametophytes are large, thallose and often perennial causing them to resemble Marchantia.

• ORDER MARATTIALES
  • Family Marattiaceae: Angiopteris, Christensenia, Danaea, Marattia, Archangiopteris (?), Psaronius, Scolecopteris.

CLASS PTERIDOPSIDA [=FILICOPSIDA, POLYPODIOPSIDA]

These plants are primarily rhizomatous and leptosporangiate (text with tooltip) A leptosporangium is a small, usually stalked, sporangium that develops from a single superficial cell. Contrast this with a eusporangium. with sporangia growing from sori on the undersides of the leaves.

• ORDER OSMUNDALES
  • These plants have a very complete fossil history which goes back to the Permian. The plants have a short erect stem with persistent leaf bases. The leaves are large with dichotomous venation leaves. Sporangia are intermediate between a leptosporangiate condition and a eusporangiate condition; they have a unistratose (text with tooltip) Comprised of a single-cell layer, e.g. the leaves of most bryophytes. wall and open by a longitudinal slit. The sporangia never occur in a sorus (text with tooltip) A sorus is a fertile region (sporangium-bearing region) on a leaf. . The gametophyte is large (up to 5 cm long) and photosynthetic.
  • Family Osmundaceae: Osmunda, Leptopteris, Todea

• ORDER HYMENOPHYLLALES
  • The filmy ferns occur mainly in the southern hemisphere and in the tropics. Most are small, some exist only as gametophytes with reproduction by means of gemmae. The leaves are thin, unistratose and the stem is protostelic. Sori are marginal and are surrounded by a cup-shaped indusium. The gametophytes are filamentous and branched.
  • Family Hymenophyllaceae: Hymenophyllum, Cardiomanes, Hymenoglossum, Rosenstockia, Serpyllopsis, Sphaerocionium(?), Mecodium(?), Microtrichomanes, Abrodictyum, Callistopteris, Cephalomanes, Crepidomanes, Didymoglossum, Polyphlebium, Trichomanes, Vandenboschia.

• ORDER GLEICHENIALES
  • This order has a fossil history which may go to the Carboniferous. The plants are mainly tropical or subtropical. Leaves have indeterminate growth which allows them to approach 6 m or more in length. The leaves have dichotomous pinnae with sori occurring on the veins (no indusia). Sporangia occur on a short stalk and have an oblique annulus. The stem is rhizomatous and ranges from protostelic to solenostelic (text with tooltip) An amphiphloic siphonostele (=solenostele) is a type of siphonostele with phloem in rings on the inside and outside of the xylem. . The gametophyte is liverwort-like, thalloid with a midrib.
  • Family Gleicheniaceae (incl. Dicranopteridaceae, Stromatopteridaceae): Dicranopteris, Diplopterygium, Gleichenella, Gleichenia, Sticherus, Stomatopteris.
  • Family Dipteridaceae (incl. Cheiropleuriaceae): Cheiropleuria, Dipteris.
  • Family Matoniaceae: Matonia, Phanaerosorus.

• ORDER SCHIZAEALES
  • This order has a fossil history which dates from the Jurassic. Mainly tropical, but Lygodium occurs in Pennsylvania. The sporangium has a thick stalk and an annulus which forms an apical cap (a longitudinal slit in Lygodium. Sporangia may be covered by an indusium-like flap and do not occur in sori. The leaves are quite variable (small to up to 30 m long). Stems are protostelic to dictyostelic. The gametophytes are filamentous or carrot-like.
  • Family Lygodiaceae: Lygodium.
  • Family Anemiaceae (incl. Mohriaceae): Anemia, Mohria.
  • Family Schizaeaceae: Actinostachys, Schizaea, Anachorpteris*.

• ORDER SALVINIALES
  • These plants are heterosporous (text with tooltip) Heterosporous plants have sporangia that produce spores of different sizes: megaspores (large) and microspores (small). Megaspores produce archegoniate gametophytes, and microspores produce antheridial gametophytes. with gametophytes rarely exceeding the bounds of the spore wall. The plants differ vegetatively though they are all aquatic or semi-aquatic. The Marsiliaceae are aquatic or semi aquatic, rhizomatous with leaves which resemble four-leaf clovers. The rhizomes have a solenostele. The Salviniaceae are floating ferns with highly reduced stems (usually protostelic when present). Sporangia are contained within modified, seed-like leaves called sporocarps.
  • Family Marsileaceae (incl. Pilulariaceae): Marsilea, Pilularia, Regnellidium.
  • Family Salviniaceae (incl. Azollaceae): Azolla, Salvinia.

• ORDER CYATHIALES
  • These plants are leptosporangiate ferns with a tree-like growth habit. They have a fossil history which goes back to the Jurassic. Tropical to subtropical, these plants are very large. The trunks often exceed 20 m and the leaves may approach 7 m long. The sori are rounded on veins and are sheathed by a globose indusium. Dehiscence occurs by a transverse slit. The gametophyte is thalloid with a midrib.
  • Family Thyrsopteridaceae: Thyrsopteris.
  • Family Loxomataceae: Loxomopsis, Loxoma.
  • Family Culcitaceae: Culcita.
  • Family Plagiogyriaceae: Plagiogyra.
  • Family Cibotiaceae: Cibotium.
  • Family Cyatheaceae (incl. Alsophilaceae, Hymenophyllopsidaceae): Alsophilia, Cyathea, Gymnosphaera, Hymenophyllopsis, Sphaeropteris.
  • Family Dicksoniaceae (incl. Lophosoriaceae): Calochlaena, Dicksonia, Lophosoria
  • Family Metaxyaceae: Metaxya.
  • Incertae Sedis: Amphidesmium, Cnemidaria, Lophosoria, Trichosorus.

• ORDER POLYPODIALES
  • This is the largest order of ferns, and it has a fossil history which dates to the Jurassic. The leptosporangia have a longitudinal annulus and a transverse slit which allows for a catapult-like spore discharge. Sori are usually covered by an indusium, which, when present, are centrally or laterally attached. The rhizome is usually dictyostelic or solenostelic and covered with scales and hairs. Two or more vascular bundles occur in the petiole, and they fuse in the rachis. The gametophyte is small, photosynthetic and cordate.
  • Family Lindsaeaceae (incl. Cystodiaceae, Lonchitidaceae): Cystodium, Lindsaea, Lonchitis, Odontosoria, Ormoloma, Sphenomeris, Tapeinidium, Xyropteris.
  • Family Saccolomataceae: Saccoloma
  • Family Dennstaedtiaceae (incl. Hypolepidaceae, Monachosoraceae, Pteridiaceae): Blotiella, Coptidipteris, Costaricia, Dennstaedtia, Histiopteris, Hypolepis, Leptolepia, Microlepia, Monachosorum, Oenotrichia, Paesia, Pteridium.
  • Family Pteridaceae (incl. Acrostichaceae, Actiniopteridaceae, Adiantaceae, Anopteraceae, Antrophyaceae, Ceratopteridaceae, Cheilanthaceae, Cryptogrammaceae, Hemionitidaceae, Negripteridaceae, Parkeriaceae,Platyzomataceae, Sinopteridaceae, Taenitidaceae, Vittariaceae): Achrostichum, Actinopteris, Adiantopsis, Adiantum, Aleuropteris, Afropteris, Anathacorus, Anetium, Anogramma, Anopteris, Antrophyum, Argyrochosma, Aspidotis, Astrolepis, Austrogramme, Bommeria, Botryogramma, Cassebeera, Ceratopteris, Cerosora, Cheilanthes, Cheiloplecton, Chrysochosma, Chrysodium, Coniogramme, Cryptogramma, Dictyogramme, Doryopteris, Eriosorus, Haplopteris, Hecistopteris, Hemionitis, Hemionanthes, Holcochlaena, Holttumia, Holttumiella, Jamesonia, Llavea, Mildella, Monogramma, Negripteris, Nephropteris, Neurocallis, Neurosorus, Notholaena, Notogramme, Ochropteris, Onychium, Ormopteris, Parahemionitis, Pellea, Pentagramma, Pityrogramma, Pityromeria, Platytaenia, Platyzoma, Polytaenium, Pteris, Pterozonium, Radiovittaria, Rheopteris, Schizolepton, Scoliosorus, Syngramma, Taenitis, Trachypteris, Vaginularia, Vittaria.
  • Family Aspleniaceae: Asplenium, Boniniella, Camptosorus, Loxoscaphe, Pleurosorus, Phyllitis, Ceterach, Thamnopteris, Antigramma, Holodictyum, Schaffneria, Sinephropteris, Hymenasplenium.
  • Family Thelypteridaceae: Thelypteris, Cyclosorus, Ampeltopteris, Chingia, Amphineuron, Cyclogramma, Christella, Cyclosorus, Glaphyropteridopteris, Goniopteris, Meniscium, Menisorus, Mesophlebion, Pelazoneuron, Plesioneuron, , Pneumatopteris, Pronephrium, Pseudocyclosorus, Sphaerostephanos, Stegnogramma, Steiropteris, Trigonospora, Phegopteris, Pseudophegopteris, Macrothelypteris, Amauropelta, Coryphopteris, Metathelypteris, Oreopteris, Parathelypteris.
  • Family Woodsiaceae (incl. Athyriaceae, Cystopteridaceae): Athyrium, Diplazium, Callipteris, Monomelangium, Ancystopteris, Cheilanthopsis, Cornopteris, Cystopteris, Deparia, Lunathyrium, Dryoathyrium, Athyriopsis, Dictyodroma, Diplaziopsis, Gymnocarpium, Currania, Hemidictyum, Homalosorus, Protowoodsia, Pseudocystopteris, Hymenocystis, Rhachidosorus, Woodsia.
  • Family Blechnaceae (incl. Stenochlaenaceae): Blechnum, Brainea, Doodia, Pteridoblechnum, Sadleria, Salpichlena, Steenisioblechnum, Stenochlaena, Woodwardia, Anchystia, Cheiniopteris, Lorinseria.
  • Family Onocleaceae: Matteuccia, Onoclea, Onocleopsis, Pentarhizidium.
  • Family Dryopteridaceae (incl. Aspidiaceae, Bolbitidaceae, Elaphoglossaceae, Hypodematiaceae, Peranemataceae): Ctenitis, Dryopteris, Elaphoglossum, Polystichum, Acrophorus, Acrorumohra, Adenoderris, Arachnoides, Altaxipteris, Bolbitis, Egenolfia, Coveniella, Cyclodium, Cyrtogonellum, Cyrtomidictyum, Cyrtomium, Didymochlaena, Dryopolystichum, Dryopsis, Nothoperanema, Microstaphyla, Peltapteris, Hypodematium, Lastreopsis, Leucostegia, Lithostegia, Lomogramma, Maxonia, Megalastrum, Oenotrichia, Olfersia, Peranema, Phanerophlebia, Papuapteris, Plecosorus, Polybotrya, Polystichopteris, Revwattsia, Stenolepia, Stigmatopteris, Teratophyllum.
  • Family Lomariopsidaceae (incl. Nephrolepidaceae): Cyclopeltis, Lomariopsis, Nephrolepis, Thysansoria.
  • Family Tectariaceae: Aenigmopteris, Arthropteris, Heterogonium, Hypoderris, Pleocnemia, Psammiosorus, Psomiocarpa, Pteridrys, Tectaria, Triplophyllum.
  • Family Oleandraceae: Oleandra.
  • Family Davalliaceae: Araiostega, Davallia, Humata, Parasorus, Scyphularia, Davallodes, Pachypleuria.
  • Family Polypodiaceae (incl. Drynariaceae, Grammitidaceae, Gymnogrammitidaceae, Loxogrammaceae, Platyceriaceae, Pleurisoriopsidaceae): Acrosorus, Adenophorus, Aenigmopteris, Aglaomorpha, Anathropteris, Arthromeris, Arthopteris, Atalopteris, Belvisia, Calymmodon, Campyloneurum, Ceradenia, Chlamydogramme, Christiopteris, Chrysogrammitis, Cochlidium, Colysis, Crypsinus, Ctenitis, Ctenitopsis, Ctenopteris, Cyclopeltis, Dicranoglossum, Dictymia, Dictyoxiphium, Drymotaenium, Drynaria, Dryopsis, Enterosora, Goniophlebium, Grammitis, Gymnogrammitis, Lastreopsis, Lecanopteris, Lellingeria, Lemmaphyllum, Lepidosorus, Leptochilus, Leucostegia, Loxogramme, Marginariopsis, Megalastrum, Melpomene, Microgramma, Microphlebodium, Micropolypodium, Microsorum, Nephrolepis, Neurodium, Niphidium, Paraselliguea, Pecluma, Phlebodium, Phymatosorus, Platycerium, Pleocnemia, Pleopeltis, Pleurosoriopsis, Podosorus, Polypodiodes, Polypodiopteris, Polypodium, Prosaptia, Psammiosorus, Pseudocolysis, Pteridrys, Pyrrosia, Rumohra, Scleroglossum, Selliguea, Solanopteris, Tectaria, Tectaridium, Terpsichore, Themelium, Triplophyllum, Trogostolon, Xiphopteris, Zygophlebia.
  • Incertae Sedis: Acyatopteris, Anisocampium, Chrynephrium, Cornoathyrium, Craspedosorus, Diellia, Diplora, Kuniwatsukia, Rhachidosorus, Macrothelypteris, Nannothelypteris, Phanerophlebiopsis, Sorolepidium.