This book was originally published in 1982. Plant growth curves are progressions of plant size against time. This book reviews the theory, practice and applications of the use of fitted mathematical functions in plant growth analysis: a subject which, despite relatively distant origins, only came into prominence following the widespread availability of computing support. The author provides a very broad approach to the subject, and includes an extended coverage of the philosophical and scientific links between this topic and related fields of activity in plant science. The work is written simply for the experimenter who grows plants and makes sequential observations on them, assuming only moderate mathematical, statistical and computational expertise, and showing how much may be achieved by modest means.