Christensenia (plant) - Misplaced Pages

Genus of ferns

Christensenia
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Division:	Polypodiophyta
Class:	Polypodiopsida
Order:	Marattiales
Family:	Marattiaceae
Genus:	Christensenia Maxon
Type species
Christensenia aesculifolia (Blume) Maxon
Synonyms
Kaulfussia C.Presl

Christensenia is a genus of ferns in the botanical family Marattiaceae. The genus is confined to the Indo-Malayan region. The basal chromosome number for this genus is 2n=80.

Christensenia is unique in the Marattiaceae, because of its reticulate venation, palmately arranged leaves and radial synangia. Christensenia produces enormous amounts of spores, up to 7,000 spores per sporangium. The presence of a radial synangium is an archaic character, very similar to some of the fossil Asterothecaceae/Psaroniaceae, such as Scolecopteris. Christensenia itself has no fossil record.

Species

After the 1993 revision by Rolleri, only two species and one variety are recognized:

Christensenia aesculifolia (Blume) Maxon (type species)
- Christensenia aesculifolia var. korthalsii
Christensenia lobbiana (de Vriese) Rolleri

References

BRUMMITT, R. K. (1992) Vascular plant families and genera. Royal Botanic Gardens
Pink, A. (2004). Gardening for the Million. Project Gutenberg Literary Archive Foundation.
Rolleri, C. H. 1993. Revision of the genus Christensenia. Amer. Fern J. 83(1): 3–19.

Classification of Archaeplastida or Plantae s.l.

(major groups

Picozoa	Picomonas
Rhodelphidia	Rhodelphis
Rhodophyta (red algae)	Cyanidiophyceae Porphyridiophyceae Stylonematophyceae Compsopogonophyceae Rhodellophyceae Bangiophyceae Florideophyceae
Glaucophyta	Glaucocystophyceae
incertae sedis	Algospongia

Viridiplantae
or Plantae s.s.
(green algae &
land plants)

Prasinodermophyta	Prasinodermophyceae Palmophyllophyceae

Chlorophyta

Prasinophytina	Mamiellophyceae Pyramimonadophyceae
Chlorophytina	Nephroselmidophyceae Picocystophyceae Chloropicophyceae Pedinophyceae Chlorodendrophyceae UTC clade Ulvophyceae Trebouxiophyceae Chlorophyceae

Streptophyta

Phragmoplastophyta

Anydrophyta

Zygnematophyceae

Embryophyta (land plants)	(see below↓)

Embryophytes or Plantae sensu strictissimo

Bryophytes

Marchantiophyta (liverworts)	Haplomitriopsida Marchantiopsida Jungermanniopsida
Anthocerotophyta (hornworts)	Leiosporocerotopsida Anthocerotopsida
Bryophyta (mosses)	Takakiopsida Sphagnopsida Andreaeobryopsida Andreaeopsida Oedipodiopsida Tetraphidopsida Polytrichopsida Bryopsida

Polysporangiophytes

†Protracheophytes*

†Horneophytopsida
†Aglaophyton

Tracheophytes
(vascular plants)

†Paratracheophytes*	†Cooksoniopsida †Rhyniopsida †Renaliales

Eutracheophytes

Lycophytes	†Barinophytopsida †Zosterophyllopsida Lycopodiopsida (clubmosses, spikemosses & quillworts)

Euphyllophytes

†Eophyllophytopsida
†Trimerophytopsida

Moniliformopses	†Ibykales †Cladoxylopsida Polypodiopsida (ferns and horsetails)

Lignophytes

†Progymnosperms*	†Noeggerathiopsida †Aneurophytopsida †Archaeopteridopsida †Protopityales

Spermatophytes
(seed plants)

†Pteridosperms* (seed ferns) and other extinct seed plant groups	†Bennettitales †Calamopityales †Callistophytales †Caytoniales †Cordaitales †Corystospermales †Czekanowskiales †Gigantopteridales †Glossopteridales †Lyginopteridopsida †Medullosales †Peltaspermopsida †Pentoxylopsida †Petriellales
Acrogymnospermae (living gymnosperms)	Cycadopsida (cycads) Ginkgoales (Ginkgo) Pinopsida (conifers) Gnetopsida
Angiospermae (flowering plants)	Basal angiosperms Core angiosperms Magnoliids Monocots Eudicots

Fern classification

Basal clade

†Ibykales
- †Ibykaceae

†Cladoxylopsida

†Cladoxylales
- †Cladoxylaceae
- †Voelkeliaceae
†Hyeniales
- †Hyeniaceae
†Iridopteridales
- †Iridopteridaceae
†Pseudosporochnales
- †Pseudosporochnaceae
†Steloxylales
- †Steloxylaceae

Polypodiopsida

†Stauropterididae

†Stauropteridales
- †Stauropteridaceae

†Zygopterididae

†Rhacophytales
- †Rhacophytaceae
†Zygopteridales
- †Zygopteridaceae

Equisetidae

†Pseudoborniales †Pseudoborniaceae †Sphenophyllales †Aspidostachyaceae †Boegendorfiaceae †Boegendorfiaceae †Eviostachyaceae †Sphenophyllaceae
Equisetales	†Asterocalamitaceae †Autophyllitaceae †Honseleriaceae †Archaeocalamitaceae †Paracalamitaceae †Calamitaceae †Apocalamitaceae †Konnostachyaceae †Manchurostachyaceae †Notocalamitaceae †Schizoneuraceae †Sorocaulinaceae †Echinostachyaceae †Gondwanostachyaceae †Tchernoviaceae Equisetaceae

Ophioglossidae

Psilotales	Psilotaceae
Ophioglossales	Ophioglossaceae

Marattiidae

Marattiales	†Knorripteridaceae †Pecopteridaceae †Ptychocarpaceae †Weichseliaceae †Asterothecaceae †Danaeopsidaceae Marattiaceae

Polypodiidae

†Anachoropteridales
- †Anachoropteridaceae
- †Psalixochlaenaceae
- †Sermayaceae
†Botryopteridiales
- †Botryopteridiaceae
†Senftenbergiales
- †Senftenbergiaceae
†Urnatopteridales
- †Crossothecaceae
- †Discopteridaceae
- †Urnatopteridaceae

Osmundales

†Guaireaceae
Osmundaceae

Hymenophyllales

Hymenophyllaceae

Thyrsopteridineae	Thyrsopteridaceae Loxsomataceae Plagiogyriaceae Culcitaceae
Cyatheineae	†Tanydoraceae Metaxyaceae Cibotiaceae Dicksoniaceae Cyatheaceae

Polypodiales

Saccolomatineae	Saccolomataceae
Lindsaeineae	Cystodiaceae Lonchitidaceae Lindsaeaceae
Pteridineae	Pteridaceae
Dennstaedtiineae	Dennstaedtiaceae
Aspleniineae	Cystopteridaceae Rhachidosoridaceae Diplaziopsidaceae Hemidictyaceae Desmophlebiaceae Aspleniaceae Thelypteridaceae Woodsiaceae Onocleaceae Blechnaceae Athyriaceae
Polypodiineae	Hypodematiaceae Didymochlaenaceae Dryopteridaceae Lomariopsidaceae Nephrolepidaceae Tectariaceae Oleandraceae Davalliaceae Polypodiaceae

Taxon identifiers
Christensenia	Wikidata: Q5109183 Wikispecies: Christensenia (Marattiaceae) CoL: 3P96 EoL: 3364531 FoC: 106919 GBIF: 3229391 GRIN: 17441 iNaturalist: 446821 IPNI: 296762-2 IRMNG: 1039406 ITIS: 897972 NCBI: 491816 Open Tree of Life: 840952 POWO: urn:lsid:ipni.org:names:296762-2 Tropicos: 40008222 WFO: wfo-4000008134

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