PETTERSSON'S study (1960) which was, however, carried out on only a very few specimens collected by LINDBERG and which probably gave a false im­ pression of the variation in this species which can be seen even amongst the few sheets available at Paris (P). Twenty eight species are recognised in the area studied in this present revision, including one new species and a few new infra-specific taxa which are described for the first time. Twenty seven of these species are endemic to Macaronesia and these are grouped into eight sections. MATERIAL AND METHODS An extensive series of field studies carried out in the Canary Islands from October 1968 to August 1969 and in the Spring of 1971 has permitted observations of natural populations throughout the range of most taxa. Data on ecology, habitat, and associated species have been collected along with some 2500 herbarium specimens of Echium, including population sam­ ples. Sets of these specimens will be deposited in the following herbaria: Department of Botany, University of Reading (RNG); Botany School, Uni­ versity of Cambridge (CGE); Department of Botany, University of Leicester (LTR); Missouri Botanical Garden, St. Louis, Missouri (MO); Departamento de Botánica, Universidad de Sevilla (SEV); Royal Botanic Gardens, Edin­ burgh (E). In addition, numerous herbarium specimens from the following herba­ ria have been studied (abbreviations following LANJOUW & STAFLEU, 1964): British Museum (Nat. Hist.) London (BM); The Botanical Museum and Her­ barium, Copenhagen (C); Botany School, University of Cambridge (CGE); Herbarium Universitatis Florentinae (FI); The Herbarium, Royal Botanic Gardens, Kew (K); Private herbarium of G. Kunkel, Las Palmas (Ku); Cá­ tedra de Botánica, Universidad de La Laguna, Tenerife (LAG); The Linnean Society, London (LINN); The Hartley Botanical Laboratories, University of Liverpool (LIVU); Institut Botanique, Université de Montpellier (MPU); Museum National d'Histoire Naturelle, Paris (P); Jardín de Aclimatación de Plantas de la Orotava, Tenerife (ORT); Department of Botany, Univer­ sity of Reading (RNG); Botanischer Garten und Museum der Universität Zürich (Z).