Belongs within: Hymenophyllaceae.
Contains: Hymenophyllum subgenus Mecodium.
Hymenophyllum is one of the main groups of filmy ferns in the Hymenophyllaceae. Species are distinguished from other filmy ferns by their bivalved involucres, though molecular phylogenetic analysis suggests a reversion to a more basal tubular form in the nested Microtrichomanes (Pryer et al. 2001). Derived involucres with the immersed section cuplike are also found in the mosslike Serpyllopsis caespitosa from the southernmost part of South America.
The distinctive Australasian species bears fronds densly clad in stellate hairs mixed with close-set clavate papillae (Allan 1961).
<==Hymenophyllum Smith 1793A61 [incl. H. subg. Sphaerocionium Cop. 1937PS01, A61, Sphaerocionium Presl 1843A61]
|--H. cruentumSP09
`--+--+--H. dilatatum (Forster) Swartz 1806SP09, A61 (see below for synonymy)
| `--H. nephrophyllumSP09
`--+--+--+--H. ferrugineum Colla 1836PS01, A61 (see below for synonymy)
| | |--H. hirsutum (Linnaeus) Swartz 1801SP09, CD07 (see below for synonymy)
| | `--H. hygrometricumSP09
| `--+--H. lanceolatum [=Sphaerocionium lanceolatum]PS01
| `--‘Crepidomanes’ subg. MicrotrichomanesPS01
| |--H. digitatumSP09 (see below for synonymy)
| |--‘Microtrichomanes’ taeniatum [=Trichomanes taeniatum, Crepidomanes taeniatum]PS01
| `--‘Microtrichomanes’ vitiense [=Trichomanes vitiense]H90
`--+--+--+--H. subg. Craspedophyllum Cop. 1937 (see below for synonymy)A61
| | | |--H. armstrongii (Baker) Kirk 1878SP09, A61 (see below for synonymy)
| | | `--H. marginatumH90
| | `--H. sibthorpioidesSP09
| `--H. subg. HymenophyllumPS01
| | i. s.: H. barbatum (v. d. B.) Baker in Hooker & Baker 1867I77, I88 (see below for synonymy)
| | H. cupressiforme Labill. 1806H90, A61 [=H. tunbridgense var. cupressiforme Hooker 1864A61]
| | H. peltatum (Poir.) Desv. 1827A61 (see below for synonymy)
| | H. pumilumH90
| | H. pygmaeum Colenso 1881 (n. d.)A61
| | H. revolutum Colenso 1846 (see below for synonymy)A61
| |--H. sect. HymenophyllumPS01
| | |--*H. tunbrigenseA61, SP09 [=H. tubridgense (l. c.)PS01, Trichomanes tunbridgenseV97]
| | `--H. secundumPS01
| `--+--H. (sect. Ptychophyllum) fucoidesPS01, SP09 [=Meringium fucoidesPS01]
| `--+--Serpyllopsis caespitosaPS01 [=Trichomanes caespitosumPS01; incl. S. antarcticaM03]
| `--H. subg. HemicyatheonPS01
| `--H. baileyanumSP09 [=*Hemicyatheon baileyanumPS01]
`--+--H. inaequaleSP09
`--H. subg. MecodiumSP09
Hymenophyllum incertae sedis:
H. abruptumM03
H. aculeatumT-W89
H. aeruginosumC06
H. asplenoidesV97
H. bridgesiiM03
H. caespitosumM03
H. caudiculatumM03
|--H. c. var. caudiculatumM03
`--H. c. var. caudatumM03
H. crispum [incl. H. crispum var. brasilianum]CSL09
H. dichotomumM03
H. dicranotrichum [incl. H. chiloense]M03
H. duseniiM03
H. elegans [incl. H. elegans f. minor]CSL09
H. exsertum Wallich ex Hooker 1844 [=Mecodium exsertum (Wallich) Copel. 1938]I88
H. falklandicumM03
H. filmenofilicum Christenhusz & Schwartsburd in Christenhusz, Schwartsburd & Labiak 2009CSL09
H. infortunatum Bory de Saint-Vincent 1828BS-V28
H. levingei [=Mecodium levingei]I88
H. lyallii Hooker 1855 [=Sphaerocionium lyallii Cop. 1938, Trichomanes lyallii Hook. & Baker 1874]A61
H. magellanicum [=Didymoglossum magellanicum]M03
H. maxoniiL54
|--H. m. var. maxoniiL54
`--H. m. var. angustiusL54
H. microcarpumJ87
H. neesiiT-W89
H. nigricansM03
H. pectinatumM03
H. pilosissimumI77
H. rufumCSL09
H. sampaioanumCSL09
H. simonsianum Hooker 1860I88
H. smithiiT-W89
H. tayloriaeL03 [=Sphaerocionium tayloriaeDF97]
H. tortuosumM03
H. trapezoidaleJ87
H. urbaniJ87
H. subg. Apteropteris Cop. 1937 [=Apteropteris Cop. 1938]A61
`--H. malingii (Hooker) Mettenius 1864 (see below for synonymy)A61
H. (subg. Chilodium) bivalve (Forster) Swartz 1801H90, A61 (see below for synonymy)
H. subg. Meringium (Presl) Cop. 1937 [=Meringium Presl 1843]A61
|--H. denticulatum [=Meringium denticulatum]I77
|--H. holochilum [=Meringium holochilum]DF97
|--H. meyenianum [=Meringium meyenianum]I77
|--H. minimum Rich. 1832 [=Meringium minimum (Rich.) Cop. 1940]A61
`--H. multifidum (Forster) Swartz 1801 (see below for synonymy)A61
Nomina nuda: Hymenophyllum beccarii Squinabol 1889S89
Hymenophyllum armstrongii (Baker) Kirk 1878SP09, A61 [=Trichomanes armstrongii Baker 1868A61, Craspedophyllum armstrongii (Baker) Cop. 1947A61, Hymenophyllum cheesemanii var. armstrongii Cheeseman 1906C49, Microtrichomanes armstrongii (Baker) Cop. 1940A61; incl. H. cheesemanii Baker ex Hook. & Baker 1873A61, H. melanocheilos Col. 1885C06]
Hymenophyllum barbatum (v. d. B.) Baker in Hooker & Baker 1867I77, I88 [=Leptocionium barbatum v. d. B. 1863I88; incl. H. denticulatum var. flaccidum (v. d. B.) Clarke 1880I88]
Hymenophyllum bivalve (Forster) Swartz 1801H90, A61 [=Trichomanes bivalve Forster 1786A61, Meringium bivalve (Forster) Cop. 1938A61, Sphaerocionium bivalve Presl 1843A61; incl. Hymenophyllum pyriforme Van den Bosch 1863A61, H. spathulatum Col. 1846A61]
Hymenophyllum digitatumSP09 [=*Microtrichomanes digitatumPS01, Trichomanes digitatumPS01; incl. T. calvescensB78, T. lanceumB78]
Hymenophyllum dilatatum (Forster) Swartz 1806SP09, A61 [=Trichomanes dilatatum Forster 1786A61, Mecodium dilatatum (Forster) Cop. 1938A61]
Hymenophyllum ferrugineum Colla 1836PS01, A61 [=Sphaerocionium ferrugineum (Colla) Cop. 1938A61; incl. H. franklinianum Colenso 1846A61, H. subtilissimum Kunze 1837C49]
Hymenophyllum hirsutum (Linnaeus) Swartz 1801PS01, CD07 [=Trichomanes hirsutum Linnaeus 1753A61, *Sphaerocionium hirsutumA61, PS01; incl. Hymenophyllum boryanumC06, Trichomanes ciliatum Swartz 1787A61, H. ciliatum Swartz 1806A61]
Hymenophyllum malingii (Hooker) Mettenius 1864 [=Trichomanes malingii Hooker 1862, *Apteropteris malingii (Hooker) Cop. 1937]A61
Hymenophyllum multifidum (Forster) Swartz 1801 [=Trichomanes multifidum Forster 1786, Meringium multifidum (Forster) Cop. 1938; incl. H. alpinum Col. 1899, H. oligocarpum Col. 1899, H. truncatum Col. 1891]A61
Hymenophyllum peltatum (Poir.) Desv. 1827A61 [=Trichomanes peltatum Poir. in Lam. 1806A61; incl. H. meyeri Presl 1843A61, H. unilaterale Willd. 1810A61, H. wilsoni Hook. 1830A61, H. tunbridgense var. wilsoniC06]
Hymenophyllum revolutum Colenso 1846 [incl. H. pusillum Colenso 1880, H. zeelandicum Van den Bosch 1863]A61
Hymenophyllum subg. Craspedophyllum Cop. 1937 [=Craspedophyllum Copeland 1938, H. sect. Craspedophyllum Presl 1843]A61
*Type species of generic name indicated
References
[A61] Allan, H. H. 1961. Flora of New Zealand vol. 1. Indigenous Tracheophyta: Psilopsida, Lycopsida, Filicopsida, Gymnospermae, Dicotyledones. R. E. Owen, Government Printer: Wellington (New Zealand).
[B78] Bentham, G. 1878. Flora Australiensis: A description of the plants of the Australian Territory vol. 7. Roxburghiaceae to Filices. L. Reeve & Co.: London.
[BS-V28] Bory de Saint-Vincent, J. B. 1828. Voyage Autour du Monde, Exécuté par Ordre du Roi, Sur la Corvette de Sa Majesté, La Coquille, pendant les années 1822, 1823, 1824 et 1825. Botanique. Cryptogamie. Arthus Bertrand: Paris.
[CD07] Cantino, P. D., J. A. Doyle, S. W. Graham, W. S. Judd, R. G. Olmstead, D. E. Soltis, P. S. Soltis & M. J. Donoghue. 2007. Towards a phylogenetic nomenclature of Tracheophyta. Taxon 56 (3): E1–E44.
[C06] Cheeseman, T. F. 1906. Manual of the New Zealand Flora. John Mackay, Government Printer: Wellington.
[CSL09] Christenhusz, M. J. M., P. B. Schwartsburd & P. H. Labiak. 2009. Hymenophyllum filmenofilicum (Hymenophyllaceae, Pteridophyta): a new epipetric filmy fern from Paraná, southern Brazil. Kew Bulletin 64 (1): 175–178.
[C49] Crookes, M. W. 1949. A revised and annotated list of New Zealand Filicinae. Transactions and Proceedings of the Royal Society of New Zealand 77 (2): 209–225.
[DF97] Dassler, C. L., & D. R. Farrar. 1997. Significance of form in fern gametophytes: clonal, gemmiferous gametophytes of Callistopteris baueriana (Hymenophyllaceae). International Journal of Plant Sciences 158 (5): 622–639.
[H90] Harden, G. J. (ed.) 1990. Flora of New South Wales vol. 1. New South Wales University Press.
[I77] Iwatsuki, K. 1977. Studies in the systematics of filmy ferns III. An observation on the involucres. Botanical Magazine, Tokyo 90: 259–267.
[I88] Iwatsuki, K. 1988. An enumeration of the pteridophytes of Nepal. In: Ohba, H., & S. B. Malla (eds)The Himalayan Plants vol. 1. The University Museum, University of Tokyo, Bulletin 31: 231–339.
[J87] Judd, W. S. 1987. Floristic study of Morne La Visite and Pic Macaya National Parks, Haiti. Bulletin of the Florida State Museum—Biological Sciences 32 (1): 1–136.
[L03] Lindsay, S. 2003. Considerations for a revision of the fern family Vittariaceae for Flora Malesiana. Telopea 10 (1): 99–112.
[L54] Lötschert, W. 1954. Beitrag zur Pteridophyten-Flora von Mittel-Amerika. Senckenbergiana Biologica 35 (1-2): 109–119.
[M03] Macloskie, G. 1903. Pteridophyta, ferns and fernlike plants. In: Scott, W. B. (ed.) Reports of the Princeton University Expeditions to Patagonia, 1896–1899 vol. 8. Botany pp. 127–138. The University: Princeton (New Jersey).
[PS01] Pryer, K. M., A. R. Smith, J. S. Hunt & J. Y. Dubuisson. 2001. rbcL data reveal two monophyletic groups of filmy ferns (Filicopsida: Hymenophyllaceae). American Journal of Botany 88 (6): 1118–1130.
[SP09] Schuettpelz, E., & K. M. Pryer. 2009. Evidence for a Cenozoic radiation of ferns in an angiosperm-dominated canopy. Proceedings of the National Academy of Sciences of the USA 106 (27): 11200–11205.
[S89] Squinabol, S. 1889. Res Ligusticae. VII.—Cenno preliminare sulla flora fossile di Santa Giustina. Annali del Museo Civico di Storia Naturale di Genova, Serie 2a, 7: 73–76.
[T-W89] Tenison-Woods, J. E. 1889. On the vegetation of Malaysia. Proceedings of the Linnean Society of New South Wales, series 2, 4 (1): 9–106, pls 1–9.
[V97] Ventenat, C. 1797. Extrait d’un mémoire sur les fougeres, de M. Smith. Bulletin des Sciences, par la Societé Philomathique de Paris 1 (9): 71–72.