Considerations about propagation and ornamental use of rare or threatned plants
of state of Rio Grande do Sul, Brazil
The extraction of wild plants for commercialization, besides of being an illegal and not a sustainable activity, is
considered one of the major causes of extinction. The introduction of exotic plants is considered the second major
threat to the world biodiversity conservation. This practice has been devoted lately to the commerce of ornamental
plants and is the cause of the invasion of many of these ones. The utilization of native plants for ornamentation
reduces considerably the risk of biologic contamination when these plants escape from their cultivated areas. Their
propagation in legalized nurseries reduces the pressure for collecting in nature. However, in regard to the use of rare
plants or plants threatened from extinction in ornamentation, questions like the pressure imposed by collecting, the
intra and inter species genetic variability and the selection of varieties must be considered. This paper discusses these
and other questions – like the concept of native species, the propagation of species threatened from extinction and the
proliferation of certain varieties at the expense of others – that are relevant to those who wish to promote the use of
native plants in ornamentation and in landscaping.