On the Capsule Formation, a Rare Case, with Special Reference to the Sterility in Iris japonica THUNB

Abstract

1. Iris japonica, an allotriploid plant (YASUI, 1939), produced some capsules as a rare case in the next year of the transplantation; but in the subsequent years those stocks bore no capsule.
2. The ratio of the number of the riped capsules to that of the flowers is 0.008%(Table 1). This ratio is remarkably small when. compared with the calculated ratio induced from the number of the viable pollen grains and that of the embryo sac with normal structure.
The causes of a high sterility in this plant were discussed, and the vigorous vegetative development of the stolones is considered as an important cause.