Development of ovule and seed in Stanfieldiella imperforata (Commelinaceae)

The development of ovule and seed of Stanfieldiella imperforata was studied. As in all other monocotyledons studied, both integuments are dermally initiated. The seed coat of Stanfieldiella is formed by the outer layer of the inner, and the silicified, innermost layer of the outer integument, the other cell layers of the outer integument forming a loose cover around the seed. These testa characteristics are rather unique among the Liliatae. The commelinaceous seed is typically operculate and provided with a micropylar collar, two features also found in Zingiberales. In both taxa the ontogeny is identical, which suggests a more or less close relationship between Commelinaceae and Zingiberales.