Book excerpt: Rhythmic Phenomena in Plants, Second Edition focuses on the study of biological clocks in all kinds of plants, from unicellular algae to flowering trees. This book discusses the patterns of plant movement, parameters of rhythms and how to calculate them, and rhythms that match and do not match environmental periodicities. The mechanism of circadian timing, circadian rhythms in angiosperms, comparison between dinoflagellates and other rhythmic organisms, and semilunar and lunar rhythms are also elaborated. This publication likewise covers the measurement of day length in photoperiodism, circannian rhythms in plants, oscillations with short periods in leaves and roots, and streaming in a slime mold. This edition is valuable to biologists intending to contribute to the study of biological timing.