Growth forms in the Alismatales. I. Alisma triviale and species of Sagittaria with upright vegetative axes

Publisher Website
Google Scholar
Abstract
Various aspects of the growth form of seven species of Alisma and Sagittaria were investigated. Of the four studied in detail, all have a short, upright stem which undergoes apical bifurcation to form the inflorescence and a continuation vegetative axis. Each season, three inflorescences are initiated in a distinct developmental sequence while phyllotaxy of the successive vegetative phases continues uninterrupted. The symmetry and development of both inflorescence and continuation growth are precise and similar in the species studied. There is greater variation in the pattern of development of axillary buds. This includes second-order axes attached directly to the parent plant (Alisma triviale), a new plant formed by each axillary stolon some distance away (Sagittaria latifolia and S. cuneata), or a whole sympodial system of stolon segments from each axillary bud as in Sagittaria subulata. Seed germination and seedling stages are very similar, and all show spiral phyllotaxy from the outset. The pattern of organization of each species remains relatively constant within and between different populations.