Although some species do remain to be discovered, the difference between these estimates is mostly one of different taxonomic concepts. Most will be in the moist tropics, especially remote parts of Latin America. The bryophytes comprise about 8000 mosses and 6000 liverworts. Although distributed throughout the world, most species occur in cool or temperate, consistenty moist climates, such as temperate South America. Temperate rainforests have the greatest diversity of lichens, but in arctic and alpine habitats lichens comprise most of the vegetation.
Tropical lichens are much less well known, especially as they tend to grow in forest canopies.
There are some 1040 species. Their highest recorded diversity is in the N. and W. Atlantic Ocean, followed by the seas around Japan. They include the kelps, with fronds up to a hundred metres long, and the wracks or 'seaweeds' of the rocky shore. As with other algal groups, the richest floras are those of the seas around Japan, the tropical and subtropical W. Atlantic, and the N. Atlantic. A recent revision recognises 440 taxa, the highest numbers from India and Asia.