Genus Lepicolea in Family Lepicoleaceae

Genus Description

Lepicolea is a well-supported genus in the hepatic flora, placed by Söderström et al. (2016) in the small, mainly Australasian family Lepicoleaceae, though some authors treat it as a subfamily (Lepicoleoideae) within the Trichocoleaceae. Global checklists list about sixteen accepted species (Söderström et al., 2016), with a broadly Southern Hemisphere distribution spanning New Zealand, Tasmania, southern South America, and the Subantarctic islands. The type species, L. pleurophylla, is central to the concept of the genus (Dumortier, 1835). Characteristic plants are large, soft, freely branched foliose liverworts, usually green to brownish, with closely imbricate, tristichously arranged leaves; leaf laminae are divided into three (rarely two) slender, acuminate segments that are incurved and often ciliate, and underleaves are present, typically similar to but smaller than lateral leaves. The inflorescences are terminal and compact; perianths are fusiform to cylindrical, trigonous below and often plicate above, and mature sporophytes have numerous, thin elaters (Engel and Schuster, 1984). The fruit is a capsule, and spores are finely papillose to reticulate.

Diversity and range centers on New Zealand, where more than half the species occur, with a secondary center in the Andes of southern South America; several taxa are endemic to the Subantarctic islands (e.g., Falkland Islands, South Georgia) and Tasmania. Populations are most common in humid forests on shaded, mossy rocks, tree trunks, and the trunks of tree ferns, often in cool, high‑rainfall settings from lowland to montane elevations. The broad austral disjunction in a southern cool‑temperate belt is typical of many Australasian–Neotropical liverwort lineages (Söderström et al., 2016).

Plants are dioecious. Male plants form dense perigonial heads; female plants produce short, lobed bracts surrounding the perianth. Although the family is not well studied cytologically, base chromosome numbers of x = 9 have been reported for L. pleurophylla (Müller, 1951–1958; cited via long‑running monographs), indicating a simple dysploid system in the lineage. No other robust life‑history or anatomical details are consistently supported across the literature.

Taxonomically, the genus has been treated as monotypic by some earlier authors, with L. pleurophylla as the sole recognized species (Hodgson, 1946; Grolle, 1972), but modern treatments recognize multiple Australasian and Neotropical taxa (Engel and Schuster, 1984; Söderström et al., 2016). Family placement remains contested: Söderström et al. (2016) adopt Lepicoleaceae, whereas some classic treatments regard the group as a subfamily within Trichocoleaceae; this remains an area of ongoing revision. Regional floristic works (e.g., Engel, 1990; Meagher, 2019) reflect these differences. No major recircumscriptions affecting Lepicolea at the generic level have been published since the latter study.

In human affairs, Lepicolea is little used; its principal interest is ecological, and it occasionally appears in specialized horticultural collections of liverworts or moss gardens, but never as a commercial ornamental. It poses no recorded invasiveness or agricultural impact.

The main conservation concerns are the fragmentation of cool, humid forest habitats and climate‑driven range shifts, especially on small islands; geneflow among disjunct populations and species limits in the complex are priority research gaps.

• Lepicolea attenuata ((Mitt.) Stephani)
• Lepicolea magellanica ((Gola) Solari)
• Lepicolea norrisii (Piippo)
• Lepicolea ochroleuca ((L.f. ex Spreng.) Spruce)
• Lepicolea pruinosa ((Taylor) Spruce)
• Lepicolea ramentifissa (Herzog)
• Lepicolea rara ((Stephani) Grolle)
• Lepicolea rigida ((De Not.) G.A.M.Scott)
• Lepicolea scolopendra ((Hook.) Dumort. ex Trevis.)
• Lepicolea yakusimensis ((S.Hatt.) S.Hatt.)