Description: Terrestrial ferns, rhizome usually creeping, but erect in a few species, covered with narrow-lanceolate scales.
Fronds 2-pinnate or more compound; main rachis bordered by 2 ridges that are continuous with the thickened margin of the basal segments of pinnae; channel of the rachis covered with long or short hairs; veins free.
Sori circular, usually indusiate (absent in 1 species), the indusium reniform or rarely peltate, glabrous or hairy.
Distribution and occurrence: World: c. 36 species, pantropical & southern temperate regions. Australia: 15 species, Qld, N.S.W., Vic., Tas., S.A.
The 45 species of Lastreopsis were resolved in two lineages, one of which is more closely related to Rumohra and Megalastrum, making Lastreopsis paraphyletic, see Labiak et al. (2014) Phylogeny and historical biogeography of the lastreopsid ferns (Dryopteridaceae). American Journal of Botany 101(7): 1-22. Lastreopsis s.s. is the lineage closely related to Rumohra and Megalastrum, for the other Labiak et al. (2014) recommended the name Parapolystichum (Keyserl.) Ching.
Text by Peter G. Wilson
Taxon concept:
Taxa not yet included in identification key
Lastreopsis nephrodioides
| | Key to the species | |
| 1 | Fronds with main rachises densely covered with spreading, dark red-brown bristle-like scales with tuberculate bases | Lastreopsis hispida |
| Fronds with main rachises covered with soft hairs or ± glabrous, sometimes with a few short, ovate or lanceolate scales | 2 |
| 2 | Rhizomes short and erect or oblique, fronds tufted; indusia glabrous; upper pinnae without basal lobes fused to rachis | 3 |
| Rhizomes short- to long-creeping; indusia absent or bearing oblong or rounded glandular hairs; upper pinnae often with basal lobes fused to rachis
Back to 1 | 4 |
| 3 | Fronds 3–4-pinnate; axes almost glabrous, except in the channel of the rachis; lamina dark green | Lastreopsis smithiana |
| Fronds 2–3-pinnate; axes covered with relatively long, soft, spreading hairs; lamina pale green
Back to 2 | Lastreopsis acuminata |
| 4 | Marginal teeth of the ultimate segments distinctly aristate | Lastreopsis munita |
| Marginal teeth of ultimate segments never distinctly aristate but sometimes acute
Back to 2 | 5 |
| 5 | Mature indusia black or very dark brown | Lastreopsis marginans |
| Mature indusia light brown, although often with a dark centre
Back to 4 | 6 |
| 6 | Ultimate segments with acute to acuminate apex | Lastreopsis decomposita |
| Ultimate segments with obtuse apex; rhizome long- creeping
Back to 5 | 7 |
| 7 | Margins of ultimate segments toothed, teeth acute with thickened tips; stipes, rachises and veins often bearing rather dense, short or long pale brown hairs, sometimes glabrous | Lastreopsis microsora |
| Margins of ultimate segments crenate; stipes, rachises and veins bearing dense, soft pale to reddish brown hairs
Back to 6 | Lastreopsis silvestris |
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