Abstract
Crown architecture of a ginger, Alpinia scabra (Zingiberaceae), was studied on Mount Halimun in a tropical submontane forest in West Java, Indonesia. An aboveground shoot of A. scabra consists of one pseudostem and many leaves distributed along the pseudostem. The pseudostem is up to ca. 2 m long. The number of nodes per pseudostem increases, up to 25, with increasing pseudostem length. Pseudostems of smaller A. scabra stand vertically, while those of larger A. scabra bend. On the contrary, the leaf surface is horizontally oriented, irrespective of the pseudostem angle at each node. The horizontal orientation of leaf surface is thought to be effective for capturing the most light per unit leaf area. The internode length decreases from the base of the pseudostem to the tip, i.e., the internode length decreases with increasing pseudostem length, accompanied with stem bending. The ontogenic changes of leaf size in large individuals of A. scabra show that leaf size increases from the base of the pseudostem to the mid-point of pseudostem, and levels off or slightly decreases thenceforth. Thus, leaves were small near the base, where pseudostems stood vertically, and increased in size with pseudostem bending. The combination of an erect pseudostem and small leaves near the base contributes to less vertical overlap of leaves there. The results of this study suggest that A. scabra distributes leaves for efficient light capture by adjusting the internode length, leaf angle, pseudostem angle, and leaf size along the pseudostem.
