Embryological studies inGlaucidium palmatum Sieb. et Zucc. with a discussion on the taxonomy of the genus

Abstract

Embryological features ofGlaucidium palmatum are as follows: the ovule is anatropous and bitegmic; the archesporium is hypodermal and multicelled, consisting of about 10 to 15 cells; all the archesporial, cells develop directly into megaspore mother cells, only three or four of which, however, generally complete meiotic divisions; before and during meiosis, dermal cells of the nucellar apical part undergo successive periclinal divisions forming a thick nucellar cap of as many as 20 cell-layers; embryo sac formation is of the Polygonum type; multiple embryo sacs occur frequently; antipodal cells are small in size and ephemeral or persistent; the inner integument is 3 to 5 cell-layers thick, and the outer integument 7 to 13 cell-layers thick; the outer integument is vascularized; a micropyle is formed by the inner integument alone; the endosperm is of the Nuclear type; embryogeny is of a type similar to the Onagrad type.

In light of evidence from embryology and other sources it seems that there is ample reason for recognizing the family Glaucidiaceae which is distinct from the Ranunculaceae and its related families. Several common embryological features suggest an affinity between the Glaucidiaceae and the Paeoniaceae.