Class
Subclass
Order
Classification
Subordinate Taxa
Nomenclature
Scientific Name:
Loxsomataceae C.Presl, Gefässbündel Farrn 31 (1847)
Type Taxon:
Description
Terrestrial ferns. Rhizomes long-creeping, bearing multicellular hairs. Fronds monomorphic, not articulated to rhizome. Laminae pinnate-pinnatifid to 3-pinnate-pinnatifid or rarely 4-pinnate at base, anadromous (NZ) or catadromous (not NZ), coriaceous, glabrous (NZ) or hairy (not NZ). Veins free. Sori terminal on veins at margins of lamina; paraphyses present; indusia urceolate; receptacles elongate and exserted, maturation of sporangia gradate. Sporangia with slightly oblique annulus, 64 spores per sporangium (NZ) or 128 (not NZ). Homosporous; spores trilete, tuberculate or rugose and pitted, lacking chlorophyll.
Taxonomy
A family of two genera and two species. The Loxsomataceae comprises terrestrial ferns with long-creeping rhizomes bearing hairs, marginal sori, urceolate indusia, exserted receptacles, sporangia with an oblique annulus, trilete spores and base chromosome numbers of 46 or 50.
The family includes two monotypic genera, Loxsoma and Loxsomopsis. Relationships to Hymenophyllaceae, Davalliaceae, Dennstaedtiaceae and Cyatheaceae have all been suggested on the basis of morphology. Evidence from comparative flavonoid chemistry of Loxsoma and Loxsomopsis indicated their isolated origins and rather distant relationship to Hymenophyllaceae and Cyatheaceae (Markham & Given 1979). However, molecular evidence (Pryer et al. 2004) suggested that Loxsomataceae is most closely related to the tree ferns, despite the lack of obvious supporting morphological, flavonoid or cytological similarities. Phylogenetic analysis by Korall et al. (2006) showed the family to be sister to a clade comprising Culcita and Plagiogyria, and that these three groups, together with Thyrsopteridaceae, are sister to the "core" tree ferns.
The family name was first published as Loxsomaceae (Presl 1847), but later corrected to Loxsomataceae. It has also been presented as Loxomataceae (e.g. Smith et al. 2006), based on the original published spelling of the genus Loxoma, a name attributed to Robert Brown but published by Cunningham (1837). However, that spelling was corrected to Loxsoma by Hooker & Bauer (1842), which is now conserved (Brummitt 2011).
Distribution
One genus in Costa Rica and South America from southern Colombia to Bolivia (Lehnert et al. 2001), and the other in New Zealand. One species in New Zealand; endemic.
Biostatus
Indigenous (Non-endemic)
| Category | Number |
|---|---|
| Indigenous (Endemic) | 1 |
| Total | 1 |
Bibliography
Brownsey, P.J.; Perrie, L.R. 2015: Loxsomataceae. In: Breitwieser, I; Heenan, P.B.; Wilton, A.D. (ed.) Flora of New Zealand — Ferns and Lycophytes. Fascicle 7. Manaaki Whenua Press, Lincoln.
Brummitt, R.K. 2011: Report of the Nomenclature Committee for vascular plants: 63. Taxon 60: 1202–1210.
Christenhusz, M.J.M.; Zhang, X.-C.; Schneider, H. 2011: A linear sequence of extant families and genera of lycophytes and ferns. Phytotaxa 19: 7–54.
Cunningham, A. 1837: Florae insularum Novae Zelandiae precursor; or a specimen of the botany of the islands of New Zealand. Companion to the Botanical Magazine 2: 222–233, 327–336, 358–378.
Hooker, W.J.; Bauer, F.A. 1842: Genera Filicum. Bohn, London.
Korall, P.; Pryer, K.M.; Metzgar, J.S.; Schneider, H.; Conant, D.S. 2006: Tree ferns: monophyletic groups and their relationships as revealed by four protein-coding plastid loci. Molecular Phylogenetics and Evolution 39: 830–845.
Kramer, K.U.; Green, P.S. 1990: Pteridophytes and gymnosperms. Kubitzki, K. (ed.) The Families and Genera of Vascular Plants. Vol. 1. Springer-Verlag, Berlin.
Lehnert, M.; Mönnich, M.; Pleines, T.; Schmidt-Lebuhn, A.; Kessler, M. 2001: The relictual fern genus Loxsomopsis. American Fern Journal 91: 13–24.
Leunis, J. 1877: Synopsis der Pflanzenkunde. Vol. 3. Edition 2. Hahn'sche Buchhandlung, Hanover.
Mabberley, D.J. 2008: Mabberley's plant book, a portable dictionary of plants, their classification and uses. Edition 3. Cambridge University Press.
Markham, K.R.; Given, D.R. 1979: The flavonoids of ferns in the isolated genera Loxsoma and Loxsomopsis. Biochemical Systematics and Ecology 7: 91–93.
Presl, C.B. 1847: Die Gefässbündel im Stipes der Farrn. Haase, Prague.
Pryer, K.M.; Schuettpelz, E.; Wolf, P.G.; Schneider, H.; Smith, A.R.; Cranfill, R. 2004: Phylogeny and evolution of ferns (monilophytes) with a focus on the early leptosporangiate divergences. American Journal of Botany 91: 1582–1598.
Smith, A.R.; Pryer, K.M.; Schuettpelz, E.; Korall, P.; Schneider, H.; Wolf, P.G. 2006: A classification for extant ferns. Taxon 55(3): 705–731.
