JOURNAL OF THEARNOLD ARBORETUMVOLUME XVI JANUARY, 1935 NUMBER 1 STUDIES IN BORAGINACEAE, X THE BORAGINACEAE OF NORTHEASTERN SOUTH AMERICA IVAN M. JOHNSTON THE present paper is a critical account of the Boraginaceae knownfrom British, Dutch and French Guiana and the adjoining portions ofBrazil, north and east of, the Amazon and the Rio Negro. A generalaccount, it is preliminary to a treatment of the Dutch Guianan speciesof the family which Prof. A. A. Pulle has invited me to prepare for his"Flora of Surinam." The borages of the Guianas have been long neglected. Such frag-mentary work as has been done on them has been restricted to the nar-row political boundaries. Though various species of the group havebeen described from the Guianas, some of them among the first basedupon South American material, the identity of the types has remainedobscure, and material in herbaria has continued to be named largely byguess or has been left to accumulate unidentified. The great referenceworks, such as DeCandolle's Prodromus, or Martius's Flora Brasiliensis,resolve little of the confusion that seems always to have enveloped ourknowledge of the Guianan Boraginaceae. They added little to theobservations all ready long available in the writings of Lamarck andPoiret. Indeed, so little known and confused were the Guianan speciesof Cordia and Tournefortia, that a few years ago, during my studiesof the Brazilian species of these genera, Contr. Gray Herb. 92: 1-89(1930), I was forced to pass over, undiscussed, the very evident rela-tions existing between the species of the Guianas and those of northernBrazil, and forced to admit that certain of the obscure species (severalof them not even listed in the Index Kewensis) might be identical andolder than the ones I was forced to accept. A careful study of theGuianan Boraginaceae has been long needed.