Fig. 1.

Floral developmental stages according to the Waddington scale (Waddington et al., 1983) with pictures taken from the experiments reported herein from early spikelet initiation at the transition of the apex to reproductive development to the stage of the fertile floret (W10), with details of selected developmental stages focused on the whole of spike development until the initiation of the terminal spikelet (W3.5) in each individual floret primordium from then onwards. (This figure is available in colour at JXB online.)