ON STRUCTURE AND ORIGIN OF SEEDLING OF PSITTACANTHUS SCHIEDEANUS (LORANTHACEAE)

The vascular structure of the ovary and seedling of Psittacanthus schiedeanus (Loranthaceae, sensu stricto) is described, followed by a brief sketch of the unique suspensor and its relationship to the developing embryo. The proembryo and suspensor at first form a single, massive body of which the embryonic pole is a meristem producing the cotyledons. The suspensor portion of this body at its maximum development consists of approximately 2000 cells, but is later crushed by the expanding embryo, and remains as a cup-like envelope of the radicular pole. The embryo itself appears to be unique among dicotyledons is being polycotylous. The functional significance of the suspensor body, and the possible systematic implications of these various aspects are brief ly discussed.