The precarious ecological status of Aloe pillansii L. Guthrie in the Richtersveld, northern Namaqualand, northwest corner of the northern Cape Province of South Africa, is examined. There is some concern over the condition of the aloe population occurring on the hill Cornellskop, the type locality. An attempt was made to recognise and analyse the main problems, natural and anthropogenic, threatening the conservation of the unique Cornellskop miniecosystem. During the research project a checklist of plants occurring on the hill was compiled. A map of Cornellskop is included (Figure 1). The general status of the aloe throughout the Richtersveld is dealt with and a map showing the overall distribution as is presently known is appended (Figure 2). The origins of the resident Richtersveld traditional herders is briefly outlined. It is postulated that future conservation of the species and the progressive degradation of the habitat is finely balanced between the restricted severe climatic niche within which the plants have evolved and ever present, progressive, attritional anthropogenic factors.

A new short-stemmed, non-twining species of Karimbolea Descoings, K. mariensis Meve & Liede, is described from Cap Ste. Marie, the southernmost tip of Madagascar.

A catalogue is presented of the succulent plants cultivated by John Blackburne (1694–1786) at Orford Hall near Warrington, Lancashire, together with biographical sketches of himself and his family. His pioneering efforts to introduce and cultivate species from North America and the tropics were widely recognised by botanists of the time, and the tradition of horticultural excellence he established led to the foundation of the Liverpool Botanic Garden in 1803.

James Justice (1698–1763) is remembered as a leading horticulturalist, author and pioneer grower of tropical exotics at Crichton, south-east of Edinburgh. New evidence is presented to show that his pine stove also housed some 25 succulents: the earliest record of a collection in Scotland.

The anatomy of IOS Group la (part of Leptocereeae and part of Echinocereeae) was examined to determine if these genera have characters that are relictual in Cactoideae. Echinocereus lacks fibrous wood and seemed distinct from genera with fibrous wood, which constitute the majority of Group la. Excluding Echinocereus and other genera with non-fibrous wood, Group la has many features presumed to be relictual: epidermal cells with ordinary shapes and thin walls, a tendency to have patches of multiseriate epidermis, hypodermis of a few layers with walls of medium thickness, cortical bundles with caps of primary phloem fibers but lacking clusters of terminal tracheids, presence of medullary bundles (and these have xylary fibers), fiber caps next to primary phloem of the stele, presence of fibrous wood and lack of any derived wood types. Derived characters that do occur are not universally present or even widespread in the group. Little evolutionary modification has occurred in Group la, except for Echinocereus.

Recent studies in Ruschia and Lampranthus show that a number of species in both big genera do not conform with the critical features of the genera. These deviating species are placed in the genera Amphibolia, Cerochlamys, Eberlanzia, Erepsia, Esterhuysenia, Octopoma, Oscularia, Rhombophyllum, and Zeuktophyllum, and the appropriate new combinations are made; one new species is described. Most genera are treated more extensively; for Ruschia and Lampranthus only the new combinations are given.

Lomatophyllum is upheld as a genus distinct from Aloe, and three new species are described. Two further species are transfers from Aloe, all with berry-like fleshy fruits. Another Madagascan novelty is described as Aloe lucileallorgeae, although fruits have not yet been examined.

Pachypodium rosulatum, most widespread and variable of Madagascan species, and its allies are reviewed in relation to 3 recently discovered new taxa. By emphasizing flower structure and presumed pollination syndromes, the aggregate can be resolved into 3 groups at species level, with varieties (and one form) covering lesser, mostly vegetative, differences. This involves making 3 new combinations.

The Ethiopian species Euphorbia sebsebei has been found in northern Kenya. The Zambian species Aloe fimbrialis has been found in south-west Tanzania, and the fresh material has made it possible to prepare a more detailed description. These are new records for East Africa.

The return of species of Lomatophyllum to the genus Aloe requires new combinations for three recently described species.

Several hybrids between species of Aloe and Gasteria (Aloaceae) have not been formally named, and they are known only by hybrid formulae. Hybrid formulae that have appeared in print are listed, and names of parent species are updated where necessary. Literature references and other available information are given.

An alphabetic reference to names in the genus Opuntia is continued from Bradleya 15: 98–112. 1997. In addition to new designations of types for certain taxa, one new combination is made for Opuntia humifusa subsp. minor.