Fig. 4.

(A–D) Actinocephalus bongardii. (A) T. Stützel with a plant at anthesis, the basal rosette has deteriorated as in P. erectifolius; umbel-like units are formed laterally to the main axis. In contrast to P. polyanthus, after a phase of vegetative growth, a set of new lateral units can be formed. (B) Longitudinal scheme. (C and D) Development of the umbel-shaped units, (C) without and (D) with annotation of the subunits and sequence of formation within the terminal unit. (E) Actinocephalus robustus forms a monopodial erect rosette growing for many years; umbel-shaped lateral inflorescences are formed in the leaf axils of 5–10 subsequent leaves. The species lacks vegetative branching (photo: Livia Echternacht).