Seed Development in Araucaria Juss

Abstract

The development of the seed coat, seed wing and food reserve tissue of the female gametophyte was studied in four species of Araucaria: A. cunninghamii, A, heterophylla, A. bidwillii and A. hunsteinii. The means of seed dispersal in each of these species were also recorded. Comparisons were made among these species and others for which published data are available.

The species differed with respect to the thickness of the seed coat and anatomical characteristics of the component layers; the thickness and nature of the nucellar layer; the relative degree of enlargement of non-fertilized ovules; the composition of the food reserves; the presence and nature of the seed wing; and the seed dispersal mechanism. The distribution of these features among the species of Araucaria for which data are available is consistent with the generally followed division of the genus into four sections.