The earliest illustration of a succulent Euphorbia is presented, dating from nearly 1500 years ago. This has been identified as Euphorbia resinifera Berg from NW Morocco. The picture is found in an illustrated manuscript herbal, a codex made of parchment, dating from the very beginning of the 7th century (dated about 600 AD). This codex, usually called the Codex Neapolitanus, has been preserved as a unique copy in the Biblioteca Nazionale, Naples. Notes are also provided on the publication of the name E. resinifera, its habitat, distribution, cultivation, and medicinal uses, together with a short description and biography in honour of the discoverer of the species, King Juba II.

A new non-clustering species of Conophytum, C. subterraneum, is described and illustrated. It is endemic to quartz vlaktes in a very small area of the Richtersveld, north of Eksteenfontein, in South Africa. Its ecology and relationships to C. achabense and other taxa are discussed.

Names and taxonomic positions of Turbinicarpus mandragora (Frič ex A. Berger) A. Zimmerman (Cactaceae) and its close allies have been quite controversially discussed in recent publications. In a rather conservative approach, only a single species, T. mandragora, with six subspecies, is recognised here: ssp. mandragora, ssp. beguinii, ssp. booleanus, ssp. pailanus, ssp. subterraneus and ssp. zaragosae.

Aloe greatheadii Schönland var. davyana (Schönland) Glen & D.S. Hardy is a widespread and commonly encountered maculate Aloe from southern Africa. A recently discovered population from Ashburton in KwaZulu-Natal occurs at the southeastern limit of its geographical distribution range, and shows sufficient morphological differences to warrant an amplification of the description of this taxon.

A natural intergeneric hybrid between Trichocereus atacamensis (Philippi) Marshall and Denmoza rhodacantha (Salm-Dyck) Britton & Rose (Cactaceae) is reported from Argentina. It is described, illustrated and named as ×Trichomoza roseiflora Font & Picca.

The history of the garden at La Mortola, near Ventimiglia, Italy, established in 1867 by Thomas Hanbury (1832–1907) with assistance from his brother, Daniel Hanbury, is reviewed. Especial emphasis is placed on the catalogues of the garden by Kurt Dinter (1897) and Alwin Berger (1912), both of whom were curators of the garden and renowned botanists in the field of succulent plant study.

Rimacactus, a new genus within subtribe Borzicactinae of the Cactaceae, is named for the species formerly known as Eriosyce laui Lüthy.A detailed description of a cultivated plant is provided, and its morphology and systematics are discussed.

Relations of L. otzenianus and L. uniflorus to the genera Drosanthemum Schwantes and Lampranthus N.E.Br. are discussed, synapomorphies for the two species are presented and similarities with the genus Malephora are described. Differences between the species are pointed out.

A note on the Saint Louis Code 2000 is contributed by Roy Mottram, and its effect on names in this index is discussed. The alphabetic index of Opuntia names is continued from Bradleya 18: 113–140. 2000. Includes eight new typifications (1 LT, 5 NT, 2 ET), and six new cultivar standards. Two paintings by Duncanson, lodged in the Kew herbarium, are reproduced here for the first time.

After consideration of available evidence, a population of Haworthia limifolia Marloth from Mpumalanga Province, South Africa, is described as a new variety, H. limifolia var. arcana G.F.Sm. & N.R.Crouch.

The nomenclatural history of a heterophyllous shrubby succulent mesemb, known from granite outcrops on the Cape Peninsula, South Africa, is discussed. Based on available information the name Ruschia pulchella (Haw.) Schwantes is considered as insufficiently known. The new combination Antimima aristulata (Sond.) Chesselet & G.F.Sm. is made to accommodate and provide an unambiguous reference for this mesemb species.

The work of Mary Maud Page, botanical artist at the Bolus Herbarium, University of Cape Town, is briefly reviewed and assessed.