Classification
 Nomenclature
Scientific Name:
Leptopteris C.Presl, Suppl. Tent. Pterid. 70 (1845)
Etymology:
From the Greek lepto- (thin), and pteris (a fern), a reference to the membranous fronds.
 Description
Terrestrial ferns. Rhizomes erect, sometimes forming a short woody trunk. Rhizome scales absent. Fronds monomorphic. Stipes hairy. Laminae 2-pinnate-pinnatifid, membranous, translucent, lacking stomata, evergreen, hairy. Sporangia scattered on abaxial surfaces, generally confined to proximal half of primary and secondary pinnae. Spores trilete, radially symmetrical, tuberculate with tubercles bearing slender echinate processes.
 Taxonomy
A genus of about seven species. Leptopteris was first recognised as a distinct genus by Presl (1845). Although closely related to Todea, two genera have usually been recognised within New Zealand, with the notable exception of Allan (1961) who included Leptopteris within Todea. Leptopteris has membranous, translucent fronds that lack stomata, and sporangia that are only sparsely scattered on the abaxial surfaces. Todea has coriaceous, opaque fronds with stomata, and sporangia that densely cover the abaxial surfaces. Phylogenetic analysis of DNA sequences from seven plastid loci (Metzgar et al. 2008) confirmed that both groups were monophyletic and sister to each other.
 Key
1Laminae elliptic in outline; basal pair of pinnae 1–20 mm long; primary pinnae 6–23 mm wide; stipes usually 20–125 mm long; ultimate lamina segments bent at 90º to the plane of the frondsuperba
Laminae ovate to triangular in outline; basal pair of pinnae 50–120 mm long; primary pinnae 25–55 mm wide; stipes 110–480 mm long; ultimate lamina segments flattened in the plane of the frondhymenophylloides
 Distribution
About seven species in New Guinea, Australia, New Zealand and the Pacific; one species each in New Guinea, the Solomon Islands, New Caledonia to Samoa, Australia and Lord Howe Island. Two species endemic to New Zealand.
 Biostatus
Indigenous (Non-endemic)
Number of species and named hybrids in New Zealand within Leptopteris C.Presl
CategoryNumber
Indigenous (Endemic)3
Total3
 Cytology
n = 22 (Kramer 1990).
 Bibliography
Brownsey, P.J.; Given, D.R.; Lovis, J.D. 1985: A revised classification of New Zealand pteridophytes with a synonymic checklist of species. New Zealand Journal of Botany 23(3): 431–489.
Brownsey, P.J.; Perrie, L.R. 2014: Osmundaceae. In: Breitwieser, I; Heenan, P.B.; Wilton, A.D. Flora of New Zealand — Ferns and Lycophytes. Fascicle 4. Manaaki Whenua Press, Lincoln.
Brownsey, P.J.; Smith-Dodsworth, J.C. 2000: New Zealand ferns and allied plants. Edition 2. David Bateman, Auckland.
Kramer, K.U. 1990: Osmundaceae. In: Kramer, K.U.; Green, P.S. Pteridophytes and gymnosperms. Vol. 1. In: Kubitzki, K. (ed.) The Families and Genera of Vascular Plants. Springer-Verlag, Berlin. 197–200.
Large, M.F.; Braggins, J.E. 1991: Spore atlas of New Zealand ferns and fern allies. SIR Publishing, Wellington.
Metzgar, J.S.; Skog, J.E.; Zimmer, E.A.; Pryer, K.M. 2008: The paraphyly of Osmunda is confirmed by phylogenetic analyses of seven plastid loci. Systematic Botany 33(1): 31–36.
Presl, C.B. 1845: Supplementum Tentaminis Pteridographiae. Haase, Prague.