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Book Reviews
information by identification. Chapter two describes databases in general and provides more detail of current
taxonomic databases. Chapter three describes the use of
computers in the process of classification and outlines the
contrasting methods of phenetic vs. phylogenetic and
cladistic classification.
The fourth to seventh chapters are where the main
strength of the book lies. They describe various aspects of
identification. In chapter four the use of keys and tables for
identification is described. This provides an introduction to
chapter five, where computer methods of identification are
described. Chapter six is a short history of keys. Chapter
seven provides a range of examples and references to
identification in practice; in botany, zoology, palaeontology,
microbiology, pharmacognosy, medical diagnosis, and
miscellaneous areas. Chapter eight describes expert systems,
contrasting them with taxonomic identification.
The great merit of this volume lies in the numerous
examples and illustrations from practical situations. Many
references are made to examples of different techniques. The
material on existing databases and methods of identification
is very effectively dealt with as far as is possible in isolation
from the actual computer packages. The final chapter
contrasting expert systems with existing taxonomic systems
is particularly interesting, since it goes to the heart of
taxonomic methodology.
However, if the book has a weakness, and it is one which
is probably inevitable in a book of this size, it is in the
limited exposition of methods of classification. Only chapter
three directly addresses the fundamental problem of
classification; of how to discover and define taxonomic
groups.
The availability of computers has provided many different
methodologies for finding groups and measuring relationships, and they are based on quite distinct philosophies. The
comparison of phenetic and cladistic methods in chapter
three is very useful in this respect. However, this discussion
is partly couched in terms of the efficacy of the computer
methods in recognizing the groups they are theoretically
designed to find. The fundamental problem is not in the
contrast of methodologies, all of which have their limitations, but in the fundamental clash of philosophies of what
are taxonomic groups. For example, are taxonomic groups
polythetic or monothetic? What is the nature of taxonomic
structure? Can hierarchical classifications adequately summarize the many different patterns of natural variation?
Computers have challenged our ideas about what is a
natural classification by providing many different ways of
representing and of simplifying biological variation.
This important argument is again touched on in chapter
eight because the contrast between taxonomic identification
methods and expert systems for identification is actually a
contrast between two profoundly different philosophies. To
give a primacy to identification methods over classification
methods in a book of this sort is to put the cart before the
horse. Effective identification can only take place if the
classification is first a stable, natural one.
Even so, the most important taxonomic problem is not
one of a choice of method of classification, whether it be by
computer or not. It is how a resulting classification can be
validated. This is a problem which is not really addressed in
this volume. Nevertheless, chapter three provides a clear
summary of some contrasting classification methods. The
author seems to favour phenetic methods of classification,
which is perhaps no bad thing at a time when most other
works promote cladistics.
This book is an excellent introduction to identification
methods in taxonomy. It brings together in a very readable
way a lot of information not easily available elsewhere for
the practising taxonomist and the postgraduate student.
M. Ingrouille
OCHOA, C. M. The Potatoes of South America: Bolivia, 512
pp. 1991. Cambridge University Press, Cambridge. £75
(hardback).
This book is a detailed traditional taxonomic treatment of
the wild and domesticated potatoes of Bolivia, i.e. species of
Solarium subgenus Potatoe section Petota. In series Acaulia,
Circaeifolia, Commersoniana, Conicibaccata, Cuneolata and
Megistacroloba 15 wild species, including S. botiviense, are
recognized, but within series Tuberosa 16 wild and seven
cultivated species are described. For all species and their
synonyms (33 taxa for S. chacoense), full details of
publication and of type specimens are given, followed by
detailed botanical descriptions illustrated by line drawings
and photographs, including floral dissections. Typification
and other taxonomic notes are given together with discussions of possible affinities, and habitat and distribution
(with some maps) and species examined are listed. In many
cases seed set and Fl hybrids obtained from interspecific
crosses are described.
The main taxonomic body of this book is preceded by
paintings (reproduced in colour) of plants of 18 species and
of tubers of various cultivated varieties, then an historical
review of potato collectors in Bolivia, then an outline of the
geography and climate of Bolivia. There is no proper
Introduction, but a Foreword by W. G. D'Arcy and a
Preface by the author. The book concludes with lists of
herbarium specimens examined and the resultant identifications, a list of abbreviations of herbaria etc., lists of
germplasm, literature cited, and finally an index of scientific
names of all plants, but no subject index. The book has been
translated expertly into English by Donald Ugent.
Unfortunately, this book lacks a proper introduction to
its main subject: the diversity of potatoes in Bolivia, and
presumably also their evolution. Instead, and rather
strangely, it starts with an historical review, which is chiefly
a chronological listing of who collected potatoes in Bolivia
where and when. Many collectors are mentioned, but the
accolades awarded are often out of proportion to the
importance of their collections, and in any case this account
is slightly tedious. Geography and climate are described in
a mundane and laboured way, presenting information
culled somewhat diffidently from other authorities. The
detailed verbal descriptions of mountain chains, etc. would
have been better presented as good topographical maps: the
maps of climate, etc. are rather poor, and the keys remain
in Spanish. The textual account of climate and vegetation is
confusing, moving back and forth between topics, and
interspersed with sundry etymological diversions. A more
Book Reviews
straightforward account of topography of all regions, then
climate and vegetation of each ecological province, together
with a selection of photographs illustrating the total range
and diversity, would have been preferable. The book does
contain some ecological photographs, but these are scattered
throughout the book in the guise of photographs of type
localities for sundry species, which serve little purpose. All
these accounts are disturbed by diversions on alternative
interpretations of information.
The introduction to the systematics of potatoes, Solarium
subgenus Potatoe section Petota, is rather elementary and
superficial, having only cursory reference to the taxonomic
treatments of other authors, and with no attempt to
compare them. There is no consideration of what criteria
should be used to distinguish species, and we have no
information to reveal the stance of. the author on important
issues such as species concepts. He has looked at herbarium
specimens, formed his opinions of species identities, and we
must accept these. With a brief dichotomous key we are
launched into the series Acaulia, Circaeifolia, etc. in
alphabetical order, and within these the species.
The detailed descriptions of each series and species
appear to be adequate, and sufficient information of
typification, nomenclature, chromosome numbers and
details of specimens examined are generally given. The
accounts of habitat and distribution are probably adequate,
and are occasionally augmented by inadequate point
distribution maps, which are hard to interpret since they
lack any indications of topography. Furthermore there are
discrepancies, for example 5. brevicaule is frequent near
Cochibamba in Map 9 but rare in Map 7, and likewise it
occurs near Sucre in Map 7 but not in Map 8.
Amongst all this information which is standard in
taxonomic revisions, are strangely secreted sections on
possible phenetic affinities with other species and on
crossability with other species under natural and artificial
conditions. These would have been much more valuable had
they been placed in a separate section of the book, where all
relevant information could have been considered and
discussed together, but cross-referenced to the taxonomic
treatment through the Index of Scientific Names. As it is, it
is very difficult to comprehend which species have evolved
as local deviant populations from more widespread species,
or which may be stabilized segregates from interspecific
hybridization, or whatever. Furthermore, although many
interspecific hybrids produced by the author are described,
there is little indication of their fertility or sterility.
When treating the seven cultivated species of potato, four
of which are acknowledged hybrids (!) the author persists in
applying the 'traditional Linnean system', rather than the
more appropriate International Code of Nomenclature for
Cultivated Plants. Since these are domesticated plants,
artificially selected by man, and clonally propagated
heterozygous individuals to boot, the results are patently
ridiculous with taxa such as Solarium xjuzepczukii var.
ckaisalla f. ck'oyu-ckaisalla, which is good going for a sterile
triploid with neither pride of ancestry nor hope of posterity!
Sadly Ochoa is not alone: Bukasov and Lechnovitch have
shared these fantasies.
In general the book is well produced and clearly printed
477
(except the Foreword). The text is fully illustrated with good
botanical line drawings and photographs, as well as some
artistically pleasant paintings, of selected species and tubers
as an introduction to the subject. However, the book is far
too heavy (over three pounds) and expensive (£75) for most
pockets.
Having completed the above review, I studied Hawkes,
J. G. and Hjerting, J. P. The Potatoes of Bolivia: Their
Breeding Value and Evolutionary Relationships, 472 pp.,
1989, Clarendon Press, Oxford, £45 (hardback). (See Review
in Annals of Botany 1989, 64, 606-608.) Except that it lacks
photographs of herbarium specimens and dissected flowers,
and it has no paintings, the book by Hawkes and Hjerting
is superior to that of Ochoa in every way, but especially in
its recognition of the mechanisms of evolution in Solanum
subgenus Potatoe section Petota, in its detailed account of
cytogenetics and crossability - of vital importance to plant
breeders - in its discussion of the availability of germplasm
resistant to various pests and diseases, and above all in its
clear and logical presentation. Altogether this makes it of
far greater importance to potato breeders, as well as of
greater interest to a wide range of botanists besides those
interested in potato taxonomy.
R. N. Lester
VAKHRAMEEV, V. A. Jurassic and Cretaceous
Floras and
Climates of the Earth, 318 pp. 1991. Cambridge University
Press, Cambridge. £55 (hardback).
The publication of this translation of Vakhrameev's book
represents the fulfilment of his dream that the summarized
fruits of his life's work should be translated into and
published in an English version. The Russian edition was
completed by Vakhrameev in 1985 and published posthumously in 1988. The collaboration which has resulted in this
unusual and pricey volume, has involved a Russian
translator and both Russian and English editors. The
Russian flavour of the text is said to have been deliberately
retained, which must account for the inclusion of some
whimsically translated words. A selection of rather dreary,
and largely superfluous, half-tone illustrations, Russian in
origin, have been added to the original line drawings, which
include the well-known Vakhrameev palaeogeographic
maps.
The major part of the book is the presentation of
comprehensive factual information about the successive
floral components present on the land surfaces of the Earth
for the period of time from the base of the Jurassic (c. 200
million years ago) to the top of the Cretaceous (c. 65 million
years ago), hence leading up to and extending beyond the
appearance of the flowering plants. The extracted data
derive from many published sources, but are predominantly
from the literature dealing with the floras of the great
USSR/China land mass. Coupled with the palaeobotanical
and palynological listings Vakhrameev presents his palaeoecological and palaoeoclimatological assessments and deductions, deliberately related to a context of drifting
continents as opposed to the tectonics of plates, the whole
being encompassed in less than 300 pages of text. The book
is thus succinct, is entirely systematic in its layout and is