Add to ORKGThe first volume of this flora appeared in 1979, followed by volume 2 in 1981 and volume 3 in 1985. The issue of volume 4 – containing the families Apocynaceae, Asclepiadaceae, Caprifoliaceae, Loganiaceae, Oleaceae, and Rubiaceae – means an important step towards the completion of Dr. A.C. Smith’s magnum opus. The revision of the large and difficult family of the Rubiaceae (co-authored by Dr. S.P. Darwin), in particular, must have given the author great satisfaction. The present volume follows the example set in the previous ones: detailed genus descriptions, elaborate keys to the species, whereas the species descriptions themselves are often extremely brief. This flora is rendered particularly useful by the extensive comments under each ta...