Non-vascular plants are those plants that do not use a system of vessels to transport water and nutrients between different parts of the plant.
Bryophytes (mosses and liverworts) are one kind of non-vascular plant and comprise a substantial component of the Heard Island flora, in terms of number of species, cover and biomass.
Bryophytes are found in most of the major vegetation communities and often occupy habitats unsuitable for vascular plants, such as cliff faces. A total of 44 moss and 12 liverwort species have been recorded, but more are likely to be added to these totals once recent collections have been identified.
Lichens are another kind of non-vascular plant and are common at Heard Island in all habitats with exposed rock. In fact, lichens dominate the vegetation in some areas. Thirty four species have been recorded on Heard Island, including several soil and moss-inhabiting species.