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This study was undertaken, in April 1964, at the suggestion of Prof. Dr. J. Lanjouw. The need for such a revision, was, however, stressed by the authors of the subtribe, viz. PAX et K. HOFFMANN, who, while delimiting these genera, remarked that the Systematics of both the (main) genera of this subtribe (viz. Paronychia and Herniaria) required a thorough study. By that remark they implicitly wanted to convey the difficulties encountered in studying the two genera. As a matter of fact theirs is the only account covering the whole group. There is no previous review of all the species of Paronychia, and CORE’s account (1941 of the 21 North American species is the only study of this genus. Herniaria has been studied by F. N. WILLIAMS (1896) and F. HERMANN (1937), but both the accounts are brief and sketchy reviews, and cannot be described as revisions. The present study was, therefore, undertaken to clear up the taxonomic position of these genera. The study was greatly facilitated by the extensive collections made by various workers (in some areas for the first time in history) in recent years, particularly during the past two or three decades. It is indeed immensely gratifying to note that well over 13500 herbarium sheets (about 10500 of them obtained on loan from nearly 45 herbaria) were available for study. A thorough examination of such a vast collection has necessitated a re-evaluation most of the infra-generic groupings, and, moreover, resulted in a considerable increase in the number of species belonging to the two main genera. Of the nine genera originally included by PAX et HOFFMANN in this subtribe, viz. Sphaerocoma, Corrigiola, Gymnocarpos, Lochia, Sclerocephalus, Paronychia, Siphonychia, Herniaria and Philippiella, only eight are retained in this account, the ninth (i.e. Siphonychia) is merged with Paronychia. The latter is subdivided (for the first time) into three subgenera (Siphonychia, Paronychia and Anoplonychia); the subgen |
