Sensitivae censitae: a description of the genus Mimosa Linnaeus (Mimosaceae) in the New World.
In this survey of American Mimosa, 479 species and 225 subspecies or varieties are aligned in five major groups (sections), and these in turn are divided into 78 serial or subserial divisions. The primary emphasis is on species native to South America and West Indies, those of continental North America being treated in less exhaustive detail. Significant departures from the classic taxonomy of the genus proposed by G. Bentham in 1875 are: recognition of an ostensibly primitive sect. Mimadenia, characterized by the presence of leaf-nectaries; the division of sect. Habbasia into two sections of equal rank; the reduction of genera Schrankia Willd. and Schranckiastrum Hassler to series within Mimosa sect. Batocaulon; and the reordering into subgroups of the very large and complex, haplostemonous sect. Mimosa. These innovations are required to accommodate the numerous additions (±30% of the presently known total) that have been discovered in the past century, especially in Brazil south of Amazonia. An introductory chapter provides a rationale for the proposed classification and a set of hypothetical evolutionary sequences on which it is based. All taxa are keyed and described. Sixty-seven distribution maps and 27 pages of line-drawings are provided. Appendices dealing with doubtful names, a selected bibliography, a list of numbered exsiccatae studied, and an index to epithets follow the main text.