Hemidictyum is a genus of ferns with a single species, Hemidictyum marginatum, commonly known as the marginated half net fern.[3] In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), it is the only genus in the family Hemidictyaceae.[4] Alternatively, the family, along with Aspleniaceae sensu stricto, may be placed in a much more broadly defined family Aspleniaceae as the subfamily Asplenioideae.[5]

Scientific classification edit
Kingdom: Plantae
Clade: Tracheophytes
Division: Polypodiophyta
Class: Polypodiopsida
Order: Polypodiales
Suborder: Aspleniineae
Family: Hemidictyaceae
Christenh. & H.Schneid.
Genus: Hemidictyum
H. marginatum
Binomial name
Hemidictyum marginatum
(L.) C.Presl[1]
  • Allantodia marginata Racib.
  • Asplenium limbatum Willd.
  • Asplenium marginatum L.
  • Asplenium mikanii C.Presl
  • Athyrium marginatum Milde
  • Diplazium giganteum Karst.
  • Diplazium limbatum (Willd.) Proctor
  • Diplazium marginatum Diels
  • Hemidictyum limbatum (Willd.) C.Presl
  • Hemidictyum peruvianum C.Presl


The name Hemidictyum was derived from the terms hemi (half) and diktyon (net), from the veins being netted only half-way across the pinnules.[6]

Phylogenetic relationshipsEdit

Hemidictyaceae is considered to be a sister family to Aspleniaceae s.l., believed to have diverged during the Cretaceous period.[7][8] The following cladogram for the suborder Aspleniineae (as eupolypods II), based on Lehtonen (2011),[9] and Rothfels & al. (2012),[10] shows a likely phylogenetic relationship between the Hemidictyaceae and the other families of the clade.

Aspleniineae (eupolypods II)












There is currently only one accepted Hemidictyum species, Hemidictyum marginatum.[2]


Hemidictyum is a native neotropical fern, found in Mexico, the Caribbean, Costa Rica, Guatemala, Honduras, Nicaragua, Panama, French Guiana, Suriname, Brazil, Venezuela, Puerto Rico, Bolivia, Colombia, Ecuador, and Peru.[3][11]


  1. ^ a b "Hemidictyum marginatum (L.) C.Presl". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 2019-11-28.
  2. ^ a b "Hemidictyum C.Presl". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 2019-11-28.
  3. ^ a b "Hemidictyum marginatum". Natural Resources Conservation Service PLANTS Database. USDA. Retrieved 4 Feb 2012.
  4. ^ PPG I (2016). "A community-derived classification for extant lycophytes and ferns". Journal of Systematics and Evolution. 54 (6): 563–603. doi:10.1111/jse.12229. S2CID 39980610.
  5. ^ Christenhusz, Maarten J.M. & Chase, Mark W. (2014). "Trends and concepts in fern classification". Annals of Botany. 113 (9): 571–594. doi:10.1093/aob/mct299. PMC 3936591. PMID 24532607.
  6. ^ The Fern Manual, being a description of all the best stove, greenhouse and hardy ferns by contributors to the Journal of Horticulture p.69, London, 1863
  7. ^ Maarten J. M. Christenhusz; Xian-Chun Zhang; Harald Schneider (2011). "A linear sequence of extant families and genera of lycophytes and ferns" (PDF). Phytotaxa. 19: 7–54. doi:10.11646/phytotaxa.19.1.2.
  8. ^ Maarten J. M. Christenhusz; Harald Schneider (2011). "Corrections to Phytotaxa 19: Linear sequence of lycophytes and ferns" (PDF). Phytotaxa. 28: 50–52. doi:10.11646/phytotaxa.28.1.6. hdl:10138/28050.
  9. ^ Samuli Lehtonen (2011). "Towards Resolving the Complete Fern Tree of Life" (PDF). PLOS ONE. 6 (10): e24851. Bibcode:2011PLoSO...624851L. doi:10.1371/journal.pone.0024851. PMC 3192703. PMID 22022365.
  10. ^ Carl J. Rothfels; Anders Larsson; Li-Yaung Kuo; Petra Korall; Wen- Liang Chiou; Kathleen M. Pryer (2012). "Overcoming Deep Roots, Fast Rates, and Short Internodes to Resolve the Ancient Rapid Radiation of Eupolypod II Ferns". Systematic Biology. 61 (1): 490–509. doi:10.1093/sysbio/sys001. PMID 22223449.
  11. ^ "Hemidictyum marginatum". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA). Retrieved 12 January 2018.