Davallia (deersfoot fern, hare's foot fern, shinobu fern, rabbit foot fern, ball fern)[citation needed] is a genus of about 40 species of fern. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), it is the only genus in the family Davalliaceae, which is placed in the suborder Polypodiineae, order Polypodiales.[1] Alternatively, the family may be placed in a very broadly defined family Polypodiaceaesensu lato as the subfamily Davallioideae.[2]
In 2008, a molecular phylogeneticstudy of Davalliaceae showed that none of the polyspecific genera recognized at that time were monophyletic.[8] In that same year, a revision of the family divided it into five genera.[5] One of these, Araiostegiella, was newly described. The genus Davallia was divided into two sections, namedDavallia and Trogostolon. Based on molecular phylogenetic studies, the Pteridophyte Phylogeny Group classification of 2016 (PPG I) accepts only one genus in the family, Davallia, sinking the other genera into synonymy.[1] The study on which the PPG I circumscription is based divides the genus into seven sections.[9]
Phylogeny
The following cladogram for the suborder Polypodiineae (eupolypods I), based on the consensus cladogram in the Pteridophyte Phylogeny Group classification of 2016 (PPG I),[1] shows a likely phylogenetic relationship between Davalliaceae and the other families of the clade.
Many of the species of Davallia are closely related and hard to distinguish from each other. In 1990, a treatment of Davalliaceae estimated the number of species at 110.[3] A 2008 paper listed all of the species, recognizing only 63.[5] A new species, Davallia napoensis was described in 2011.[10] The Pteridophyte Phylogeny Group classification of 2016 (PPG I) suggests there are about 65 species.[1]
The plants have furry rhizomes which cover the surface of the potting mixture as well as root down into it. The fronds are triangular in shape and about 1½ feet long by 1 foot wide. They divide into three to four pinnae which subdivide into many pinnules. Davallia are often used in hanging baskets because the rhizomes split into sections and the surface is covered quickly. Unlike other ferns, Davallia tolerate low levels of humidity.[16]
^ abcdefPPG 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. S2CID39980610.
^ abKarl U. Kramer. 1990. "Davalliaceae". pages 74-80. In: Klaus Kubitzki (general editor); Karl U. Kramer and Peter S. Green (volume editors) The Families and Genera of Vascular Plants volume I. Springer-Verlag: Berlin;Heidelberg, Germany. ISBN978-0-387-51794-0
^Harald Schneider, Alan R. Smith, Raymond Cranfill, Christopher H. Haufler, Tom A. Ranker, and Terri J. Hildebrand. 2002. "Gymnogrammitis dareiformis is a polygrammoid fern (Polypodiacee) - Resolving an apparent conflict between morphological and molecular data". Plant Systematics and Evolution234(1-4):121-136. doi:10.1007/s00606-002-0207-z
^ abcMasahiro Kato and Chie Tsutsumi. 2008. "Generic Classification of Davalliaceae". Acta Phytotaxonomica et Geobotanica59(1):1-14.
^Hong-Mei Liu, Xian-Chun Zhang, Wei Wang, Yin-Long Qiu, and Zhi-Duan Chen. 2007. "Molecular Phylogeny of the Fern Family Dryopteridaceae inferred from Chloroplast rbcL and atpB Genes". International Journal of Plant Sciences168(9):1311-1323. doi:10.1086/521710
^Eric Schuettpelz and Kathleen M. Pryer. 2007. "Fern phylogeny inferred from 400 leptosporangiate species and 3 plastid genes". Taxon56(4):1037-1050.
^Chie Tsutsumi, Xian-Chun Zhang, and Masahiro Kato. 2008. "Molecular Phylogeny of Davalliaceae and Implications for Generic Classification". Systematic Botany33(1):44-48.
^Fa-Guo Wang, Hong-Feng Chen, and Fu-Wu Xing. 2011. "Davallia napoensis, a New Species of Davalliaceae from Guangxi, China". Novon21(3):380-384. doi:10.3417/2009093
^Alan R. Smith, Kathleen M. Pryer, Eric Schuettpelz, Petra Korall, Harald Schneider, and Paul G. Wolf. 2008. "Davalliaceae". pages 443-444. In: "Fern Classification". pages 417-467. In: Tom A. Ranker and Christopher H. Haufler (editors). Biology and Evolution of Ferns and Lycophytes. Cambridge University Press. ISBN978-0-521-87411-3
^Anthony Huxley, Mark Griffiths, and Margot Levy (1992). The New Royal Horticultural Society Dictionary of Gardening. The Macmillan Press,Limited: London. The Stockton Press: New York. ISBN978-0-333-47494-5 (set).
^George W. Staples and Derral R. Herbst. 2005. "A Tropical Garden Flora" Bishop Museum Press: Honolulu, HI, USA. ISBN978-1-58178-039-0
^Barbara Joe Hoshizaki. 1981. "The fern genus Davallia in cultivation". Baileya21(1):1-42.