The growth and phenology of Metrosideros in Hawaii

Abstract

The growth and phenology of three principal varieties of Hawaiian Metrosideros were examined. All varieties have an annual flowering cycle extending over several months, usually peaking in spring or summer. The peaks of different sympatric varieties are distinct from each other. The adaptive value of periodicity in flowering may relate to reproductive isolation of different potentially cross-breeding varieties. Fruit development lasts up to one year with dehiscence of capsules occurring in the winter. Vegetative flushing of individual branches occurs twice per year in two varieties and once per year in another but is often multiphasic within a tree. A peak flushing precedes peak flowering, and subsequent flowering peaks may coincide with more flushing, if any. The growth of the trunk is continuous on all sites and is not correlated with the phenology of the tree or rainfall pattern.