Lindsaea are small dainty ferns that are easily overlooked. Three species are indigenous to New Zealand.
Recent DNA-based research (Lehtonen et al. 2010) implies that each got here independently; i.e., there were three separate dispersal events. This is because the three species in New Zealand are each more closely related to an overseas species than to each other.
The three indigenous New Zealand species are:
Lindsaea trichomanoides (also in Australia) is related to L. rufa of New Caledonia.
Lindsaea viridis (only found in New Zealand) is related to a group of species occurring from Madagascar through Malesia to western Polynesia.
Lindsaea linearis (also in Australia and New Caledonia) is related to L. microphylla of Australia.
This is a common pattern. Many New Zealand ferns are also indigenous elsewhere. Of the species only found in New Zealand, many are more closely related to overseas species than to other New Zealanders. This indicates a comparatively high level of immigration and emigration.
Lehtonen S, Tuomisto H, Rouhan G, Christenhusz MJM (2010) Phylogenetics and classification of the pantropical fern family Lindsaeaceae. Botanical Journal of the Linnean Society 163: 305-359.