Our findings are critical to the many agroforesters, horticulturalists, ecologists,and pharmacologists working with these diverse genera. For example, gum arabic is a $100 million per year business, and the two species of Acacia from which it is derived will become part of a new genus Senegalia because they are not at all related to the other African Acacias. Likewise, the Australian wattles, many of which are cultivated for wood, food, and ornament, are not related to the other Acacias and will be recognized as a different genus. Many of the genera treated in my monograph are important timber species such as carbonero (P. pittieri), as well as members with important chemical characteristics and medicinal uses. Our data will be invaluable to future chemical prospecting of plant resources and to foresters worldwide.
impact statement issue
The legume family is the third largest plant family, second only to grasses in importance to mankind. Mimosoid legumes are particularly important in tropical ecosystems as agroforesty and timber trees, providing wood and forage in marginal ecosystems and arid regions of the world. As much of the native vegetation is degraded, we see an increased emphasis put on the development and improvement of these legumes, yet we currently have little information on how they are related to one another or even how many species there are. A phylogenetic context is indispensable to the agricultural development of species in these genera, especially as we move into an era in which large portions of the genome can be examined relatively rapidly.
impact statement response
We have undertaken a study of the evolutionary relationships of the mimosoid legumes based on DNA data, as well as an understanding of their morphology. We have produced a phylogeny that demonstrates that the very large and important genus Acacia actually consists of five unrelated groups, and this genus of 1,500 species will have to be split into five smaller genera. We are also finishing a treatment of 40 genera of mimosoid legumes that will provide definitive data on how many species there are, what they are, and how to identify them.
impact statement summary
This project encompasses: 1) construction of an evolutionary tree for all genera in the "mimosa" subfamily of legumes; 2) a complete understanding of morphological evolution in this important group of legumes; and 3) an online illustrated resource that describes 40 of these genera in detail and will allow the identification of genera and species in the group.
