The Families Of The Monocotyledons

When Rolf Dahlgren and I embarked on preparing this book series, Rolf took prime responsibility for monocotyledons, which had interested him for a long time. After finishing his comparative study and family classification of the monocots, he devoted much energy to the acquisition and editing of family treatments for the present series. After his untimely death, Peter Goldblatt, who had worked with him, continued to handle further incoming monocot manuscripts until, in the early 1990s, his other obligations no longer allowed him to continue. At that time, some 30 manuscripts in various states of perfection had accumulated, which seemed to form a solid basis for a speedy completion of the FGVP monocots; with the exception of the grasses and orchids which would appear in separate volumes. I felt a strong obligation to do everything to help in publishing the manuscripts that had been put into our hands. I finally decided to take charge of them personally, although during my life as a botainst I had never seriously been interested in monocots.

To some extent classification is subjective. Taxonomists differ in the relative importance they ascribe to particular characters and in the degree of difference between related taxa they deem sufficient to constitute family or ordinal rank. About 250 monocot family names have been published. Those who have attempted an overview of the system at the family level and above in the last quarter century recognize between 45 and 103 monocot families in 14 to 38 orders. I accept 57 families in 18 orders. In Table 1 I give my ordinal allocation of the families and that of 11 recent authors to indicate where there is agreement and where there are differences to be resolved. I have constructed a dendrogram to suggest relationships and degree of advancement of the orders.I have written concise, uniform descriptions of all the families of monocots emphasizing those characters that show trends between families or occur in more than one family. Each family is illustrated by analytical drawings of the flower, fruit, seed, and usually inflorescence. Several species are usually used to show the range of major variation within families and trends toward related families.

This volume is the outcome of a modern phylogenetic analysis of the grass family based on multiple sources of data, in particular molecular systematic studies resulting from a concerted effort by researchers worldwide, including the author. In the classification given here grasses are subdivided into 12 subfamilies with 29 tribes and over 700 genera. The keys and descriptions for the taxa above the rank of genus are hierarchical, i.e. they concentrate upon characters which are deemed to be synapomorphic for the lineages and may be applicable only to their early-diverging taxa. Beyond the treatment of phylogeny and formal taxonomy, the author presents a wide range of information on topics such as the structural characters of grasses, their related functional aspects and particularly corresponding findings from the field of developmental genetics with inclusion of genes and gene products instrumental in the shaping of morphological traits (in which this volume appears unique within this book series); further topics addressed include the contentious time of origin of the family, the emigration of the originally shade-loving grasses out of the forest to form vast grasslands accompanied by the switch of many members to C4 photosynthesis, the impact of herbivores on the silica cycle housed in the grass phytoliths, the reproductive biology of grasses, the domestication of major cereal crops and the affinities of grasses within the newly circumscribed order Poales. This volume provides a comprehensive overview of existing knowledge on the Poaceae (Gramineae), with major implications in terms of key scientific challenges awaiting future research. It certainly will be of interest both for the grass specialist and also the generalist seeking state-of-the-art information on the diversity of grasses, the most ecologically and economically important of the families of flowering plants.