"If they were as rare as orchids we would probably rave about them" opens this film in the Secrets of Nature series, directed by the prolific Mary Field. The mesmerising time-lapse photography is offset by a jokey commentary voiced by EVH Emmett, then best known as the voice of the Gaumont newsreel. The flippant tone is exemplified by his comment on the range of responses to dandelions: "Some gardeners tear up the lawn and lay crazy paving, some tear up a high cliff and jump off"..