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Summary Crabbea veilutina and Dicliptera laxata exhibit a highly complex and complicated inflorescence organization in which sectorial anisoclady plays an essential role. The capitule-Iike axillary inflorescences of Crabbea are interpreted as indeterminate thyrses, in which all axes are merged into a flat receptacle (coenosome). Due to extreme anisoclady the cymes (dichasia) are produced in an alternate manner (‘alterniclady’). Both fertile and sterile bracts of the thyrse as well as the prophylls within the cymes are placed at the periphery of the coenosome and form an involucrum around the flowers. Empirical and interpretive diagrams are given in Fig. 9a–c. Comments are made to some additional species, from which C. nana and C. angustiflolia deserve special mention. In Dicliptera the basic inllorescence element is a few-flowered head embraced by two median bracts. It is interpreted as a condensed, indeterminate, alternicladic spike (Fig. 18). These elements (‘spikelets’) are combined to fan-like structures. The formation and radial arrangement of the spikelets is difficult to explain (Fig. 14). The fans emerge from the leafaxils and are multiplied by accessory shoot formation. The total inllorescencc is a most complex thyrse-like system (Fig. 11 a). The inflorescence organization of the two plants is (formally) derived from that of Phaulopsis imbricata. In terms of T roll’s synllorescence concept Crabbca and Dicliptera exhibit truncate polytelic synllorescences; Dicliptera provides a perfect example of a polytelic synflorescence of second grade. |
