Finally, I wish to record the debt of gratitude which we owe to Dr. Hill, Director of the Royal Botanic Gardens, Kew, to Mr. Cotton, the Keeper of the Herbarium, to Dr. Stapf, the late Keeper, and to the Staff of the Herbarium, most particularly Mr. C. H. Wright, Mr. Dunn, Miss Hughes, and Mr. Skan for the numerous acts of kindness and help which they have given us, making thus our work light and pleasant. A. F. BROUN. “OAKLANDS,” AMPTHILL, _Dec. 18th,_ 1925. Note.—Owing to various causes, for which we are not responsible, the printing of this book has been considerably delayed. Mrs. Crowfoot, to whom reference has been made above, is now bringing out a companion volume to this, containing drawings of various plants from the Northern and Central Sudan. My dear wife, who shared all my work, died on the 11th April, 1927. A. F. BROUN. AMPTHILL, _March 20th,_ 1928. ABBREVIATIONS. ab. stands for about acumin. „ „ acuminate alt. „ „ alternate anth. „ „ anther or anthers artic. „ „ articulate cal. „ „ calyx capit. „ „ capitulum caps. „ „ capsule cm. „ „ centimetre cor. „ „ corolla diam. „ „ diameter excl. „ „ excluding filam. „ „ filament or filaments fl. „ „ flower or flowers fld. „ „ flowered fol. „ „ foliolate foll. „ „ follicle or follicles fr. „ „ fruit or fruits ft. „ „ foot or feet hermaphr. „ „ hermaphrodite heterog. „ „ heterogamous homog. „ „ homogamous hypog. „ „ hypogynous in. „ „ inch or inches incl. „ „ including infl. „ „ inflorescence interpet. „ „ interpetiolar invol. „ „ involucre l. „ „ leaf or leaves lanc. „ „ lanceolate lin. „ „ linear obl. „ „ oblong obov. „ „ obovate opp. „ „ opposite pan. „ „ panicle or panicles ped. „ „ peduncle or peduncles pedic. „ „ pedicel or pedicels per. „ „ perianth pet. „ „ petiole or petioles rac. „ „ raceme or racemes recept. „ „ receptacle segm. „ „ segment or segments st. or sta. „ „ stamen or stamens