The second edition bundles the two parts and is only sold as a set.
About 15 years after the first edition of the Illustrated Handbook of Succulent Plants: Aizoaceae A-E, a wealth of changes can be reported for the family Aizoaceae, and this second edition brings a completely new survey over all taxonomic units from subfamilies down to species and subspecies; each critically examined. Of the presently known 2956 species, 1594 have been accepted and are described here, arranged in 147 genera. Six genera have been newly described since 2001, namely Brianhuntleya, Hammeria, Knersia, Phiambolia, Ruschiella, and Volkeranthus, and only one has been placed newly into synonymy (Caulipsilon). All synonymous genus names are treated with the valid genus names. Preliminary molecular studies are referred to, for which different groups of markers at different levels like species, genera, subgenera, and further ranks have been used. The basic division into four subfamilies is supported by more recent studies, yet with some genera being shifted. Furthermore, the geographical distribution of each genus is shown on one map each: either worldwide, or restricted to Southern Africa. For these latter, the main rainfall seasons are delimited by blue lines in order to offer also parameters for cultivation.
This second edition provides a comprehensive list of the latest taxonomy including the updated relevant plant data. Following an introduction to the leaf-succulent family Aizoaceae, including keys to the subfamilies and genera, all genera with keys to the subgenera and succulent species are described in detail.
Dr. Heidrun (Heidi) E.K. Hartmann has worked as senior lecturer in the rank of a professor at the University of Hamburg, Germany, teaching and researching in the fields of General Botany, especially Systematics of plants, from 1970 until 2007. She published well over 120 books and articles, mainly on the ecology and taxonomy of the Aizoaceae, based on her thorough knowledge of this plant family, derived from extensive field work in Africa, where she spent 4 to 12 weeks every year between 1968 and 2014.
From the reviews of the first edition:
"This series is a reference manual for taxonomists and horticultural cognoscenti. It compiles up-to-date information not readily available from other sources [...] . This series is invaluable to identify succulents, by either picture keying [...] or by formal text keying. [...] The volumes are well produced. [...] this is an excellent series, a significant contribution to the literature, and a superb production. [...] This fine series is a boon to all aficionados of succulents [...] ."
– Rudolf Schmid, Taxon, Vol. 52, 2003
"Current studies of Aizoaceae [...] collectively amount to several thousand pages of insight, prescience, hard-won data, and metaphor. Condensing this rich and troublesome legacy into a handbook was a massive task, which could only have been marshaled by Dr. Heidi Hartmann. [...] the black and white graphics [...] are beautifully done. The books are well-bound [...] . The work as a whole will become an indispensable reference for anyone with a serious interest in these seriously and wonderfully peculiar plants."
– Steven Hammer, Plant Systematics and Evolution, Vol. 232 (3-4), 2002
"The Illustrated Handbook of Succulent Plants, published under the supervision of the IOS (International Organisation for Succulent Plant Study), aims to provide a comprehensive up-to-date lexicon of all succulent plants [...] . two ponderous volumes dealing with the family Aizoaceae have now appeared. [...] we can only confirm the positive judgement expressed on the first volume of the series. An enormous mass of knowledge is packed and organised in the Handbook, producing an impressive data bank and undoubtedly a standard reference for future research."
– Lino Di Martino, Cactus & Co., Vol. 6 (2), 2002