Non-vascular land plants with a gametophyte-dominant life cycle recorded from South Africa
This listing contains taxa of plants in the division Marchantiophyta, recorded from South Africa. The Marchantiophyta are a division of non-vascular land plants commonly referred to as hepatics or liverworts. Like mosses and hornworts, they have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of genetic information.
It is estimated that there are about 9000 species of liverworts.[1] Some of the more familiar species grow as a flattened leafless thallus, but most species are leafy with a form very much like a flattened moss. Leafy species can be distinguished from the apparently similar mosses on the basis of a number of features, including their single-celled rhizoids. Leafy liverworts also differ from most (but not all) mosses in that their leaves never have a costa (present in many mosses) and may bear marginal cilia (very rare in mosses). Other differences are not universal for all mosses and liverworts, but the occurrence of leaves arranged in three ranks, the presence of deep lobes or segmented leaves, or a lack of clearly differentiated stem and leaves all point to the plant being a liverwort.
Liverworts are typically small, usually from 2–20 mm wide with individual plants less than 10 cm long, and are therefore often overlooked. However, certain species may cover large patches of ground, rocks, trees or any other reasonably firm substrate on which they occur. They are distributed globally in almost every available habitat, most often in humid locations although there are desert and Arctic species as well.[2]
23,420 species of vascular plant have been recorded in South Africa, making it the sixth most species-rich country in the world and the most species-rich country on the African continent. Of these, 153 species are considered to be threatened.[3] Nine biomes have been described in South Africa: Fynbos, Succulent Karoo, desert, Nama Karoo, grassland, savanna, Albany thickets, the Indian Ocean coastal belt, and forests.[4]
The 2018 South African National Biodiversity Institute's National Biodiversity Assessment plant checklist lists 35,130 taxa in the phyla Anthocerotophyta (hornworts (6)), Anthophyta (flowering plants(33534)), Bryophyta (mosses (685)), Cycadophyta (cycads (42)), Lycopodiophyta (Lycophytes(45)), Marchantiophyta (liverworts (376)), Pinophyta (conifers (33)), and Pteridophyta (cryptograms(408)).[5]
