Dendroconche is a small genus of ferns in the family Polypodiaceae, subfamily Microsoroideae, formally erected in 2019 to accommodate a group of species previously placed mostly in the large genus Microsorum. A molecular phylogenetic study of the subfamily found that these species formed a clade closely related to, but distinct from, Lecanopteris in the strict sense; rather than broaden Lecanopteris to absorb them, the study's authors preferred to split off three new segregate genera, one of which is Dendroconche. The genus currently comprises about eight species, with Dendroconche annabellae as the type species.
Species of Dendroconche are usually partially epiphytic ferns, growing from long, creeping rhizomes that are flattened from top to bottom and covered in brown scales; in some species the rhizome contains internal cavities. The rhizome produces two distinct kinds of roots — lateral roots that grip the surface the plant grows on, and roots from beneath that penetrate the substrate. Leaves (fronds) vary considerably within the genus, from undivided to deeply divided, and can reach up to 70 cm long by 40 cm wide; some species even produce leaves of more than one shape on the same plant. A petiole may or may not be present, and when it is, it is usually winged. Leaf veins are prominent, and the round or elongated sori (spore clusters) are borne on the underside of the fronds in typical polypod-fern fashion.
The genus is centered on the western Pacific: species occur natively in eastern Australia, parts of Indonesia, New Guinea, New Caledonia, the Solomon Islands and New Zealand, generally in rain forests at low to middle elevations. Most species have narrow distributions, but Dendroconche linguiforme is comparatively widespread and has even escaped cultivation in India.
Taxonomic acceptance of Dendroconche is not universal: as of the early 2020s the Checklist of Ferns and Lycophytes of the World recognized it as a distinct genus, while Plants of the World Online continued to treat it as a synonym of the broader Microsorum. This reflects an unresolved, ongoing debate over how narrowly to circumscribe genera within Microsoroideae.
Etymology
The name Dendroconche is Greek-derived, from dendron ("tree") and konchē ("shell"), apparently referring to the rounded leaves and growth habit of the type species, Dendroconche annabellae.
Distribution
Dendroconche species are native to eastern Australia, parts of Indonesia, New Guinea, New Caledonia, the Solomon Islands and New Zealand, growing in rain forests at low to middle elevations. Most species have narrow ranges, but Dendroconche linguiforme is widespread and has escaped cultivation in India.
Taxonomy Notes
Dendroconche was erected in 2019 after a molecular phylogenetic study of subfamily Microsoroideae found a clade of species — mostly previously placed in Microsorum — closely related to but distinct from Lecanopteris sensu stricto; the study's authors split off three new segregate genera, including Dendroconche, rather than broaden Lecanopteris. Acceptance is not universal: the Checklist of Ferns and Lycophytes of the World recognizes the genus, while Plants of the World Online treats it as a synonym of Microsorum (per GBIF, an authorship "Copel." also attaches to an older homotypic use of the name).
