The fossil history of stamens deals with "the earliest megafossil evidence of angiosperm reproductive structures" from 
Aptian deposits, and builds up with findings from later periods, adding information on the diversity of fossil stamens, and finally arriving at the profusion of new taxa in the Early Tertiary with continuous specialization of insect vectors, development of the wind pollination syndrome, etc.
All aspects of stamen morphology are discussed, including the terms anther, connective, filament, theca, etc. as well as the way they were used by different authors. Old ideas on angiosperm stamen plesiomorphic attributes are considered and evaluated against phylogenctic hypotheses for flowering plants and outgroup analysis. From this, it arises that groups that were pointed to as having plesiomorphic attributes have now been shown to be derived rather than basal angiosperms and therefore their attributes might not really help in understanding plesiomorphic ones. Phylogenetic analyses of basal angiosperms may place different groups at the base of different cladograms which could change present ideas about the evolution of stamens depending on which groups are considered to be basal.
Diversifications from a basal anther plan are demonstrated; different anther sizes, different behaviour once anthers are dehisced, the relationship between pollination biology and anther shape, anther shape and floral construction, anther shape and anther histology, anther shape and systematics are the subjects (subtitles) in this chapter which ends by trying to mark major evolutionary trends: from basifixed with massive connective to dorsifixed with narrow, short, connective and bulging pollen sacs. Increased ratio polliniferous to non polliniferous tissue is apparently the result of the appearanceof a more elaborate perianth taking over the protective and attractive task previously performed by stamens.
The discussion on the possible homology of stamens and carpels is really interesting as is the conclusion: whereas the evidence suggests a leaflike origin for the carpel, this is not the case for the stamen.
Chapter six-Heterochrony in the Anther-tries to evaluate changes in ontogenetic rates or timing during evolution. This interesting approach seems too incipient and faces several problems, particularly with respect to the study of anther development during the early stages which are "precisely the stages that may be subject to temporal change" in the examples cited.
The Diversity of Endothecial Patterns in the angiosperms is treated through the review of taxa of different hierarchies analyzing current knowledge on endothecial thickenings and concluding that "variation in endothecial patterns is most usefully employed for phylogenetic studies within the family ... the only level at which it has contributed significantly". It is also indicated that data on endothecial thickenings are mainly corroborative so that they are better used to support previous hypotheses, and although these varied patterns are important for descriptive purposes, three main ones have proved phylogenetically informative: helical, baseplate, and U-shaped.
Anthers may have calcium oxalate packages (OP) which occur in some families-mainly Solanaceae and Ericaceae. An OP is present in most genera of Solanaceae as well as in many taxa of Ericaceae. They are considered apomorphic and of independent origin. The question of the OP function is addressed quite extensively but no role can be assigned to them with any certainty at this time. Only a suggestion that "calcium oxalate and perhaps the unknown impurities in the OP should be considered as another kind of reward, along with nectar, pollen, oils, etc., offered by flowers to encourage pollination".
Anther adaptation in animal pollination is always an attractive subject and here it is pointed out that anthers can themselves be primary attractants as well as perianth parts; many interesting plant-pollinator interactions are described.
Two chapters refer to the use of stamen characters in two families; one demonstrates the importance of androecial characters in reflecting natural relationships in the Asclepiadaceae whereas the other points out that although stamens are less frequently considered than other floral parts in morphological and systematic studies, they show a great diversity, some brought about by different developmental processes.
A revision of old and useful new methods for studying stamen specimens under light and electron microscopes, histochemistry and molecular techniques, as well as references for the study of pollen and pollination are given in chapter 12.
Although each chapter closes with the literature cited and each uses one to four and a half pages for this purpose, there is a whole chapter (the last) on bibliography on stamen morphology and anatomy. This will be extremely useful for students of stamen morphology, especially since it ends with a subject and a systematic index.
A few minor errors have escaped proof reading (the authors might have noticed this by now) and their correction would improve next editions: Chapter 8, Fig. 18, figure legend indicates a double arrow where there is just one. Chapter 9, Fig. 5 is referred to as Hibbertia dentata in the text, whereas the figure legend indicates it is Melicytus lanceolatus; some figures are several pages away from their reference in the text which subtracts fluency from the reading. Chapter 11, Fig. 52, the meaning of R in the figure is not indicated in the legend. Chapters two and three refer very frequently to structures and features in papers by different authors; although photographs of these structures might not have been available, simple drawings might have been of extreme help for those of us who have not been in contact with representatives of the numerous families, genera and species that are considered in these chapters.
One of the first problems faced with while reading was the small type used, which made the reading rather tiresome; I must confess that by the sixth or seventh chapter I was used to the size, but it did bother me for quite some time.
I would recommend this as a very good reference book for those researchers involved in stamen studies be they morphological, phylogenetic or focused toward whatever aspect of staminal characteristics. - Paula M. Hermann, Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Argentina
Agnes Chase's First Book of Grasses: The Structure of Grasses Explained for Beginners. 4th ed. L.G. Clark and R.W. Pohl. 1996. ISBN 156098-656-5. (paper US$16.95). 127 pp. Smithsonian Institution Press, 470 L'Enfant Plaza, Suite 7lOO, Washington, D.C. 20560
The beauty of this book is in its simplicity. It works as it is intended-a "tutorial" for students in introductory agrostology classes or for the brave soul setting out on his/ her own adventure into grass identification. The first stumbling block for most students is the specialized terminology of agrostology. Chase deals with this point with the convincing example of the practicality of terminology-just how can one describe starting a car without using the words peculiar to cars. From here and through each of the 12 lessons, terminology is reinforced as it teaches. Likewise, the organization of the lessons (with the exception of the new "Lesson 12: The Bamboos and the Rices") according to spikelet types gets to the heart of understanding grass structure, starting simply and moving toward greater complexity. With this foundation, keys and grass classification become less frustrating for the beginner. Chase's voice in the Introduction concerning the importance of grasses as plants and friends of humans is as compelling today as it was when first written. One can hope that even the most reluctant student will listen to her timeless message. Additions made by Clark and Pohl include " How to Study Grasses" and "Synopsis of Grass Classification" as well as a glossary and reference list.
New students should be introduced to grasses with this text-there is no other that accomplishes so much with so little to dispel the mysteries of grass terminology and structure. And for the economically minded student, the price is right. We can thank Clark and Pohl for refreshing the spirit of Agnes Chase and presenting her to new generations of botanists and students of grasses. For Pohl, this stands as a fitting legacy to have offered at the end of his life. - Laura A. Morrison, Department of Plant Genetics, Weizmann Institute of Science, Rehovot 76100 Israel