Carpel Dehiscence in Firmiana Simplex

The young carpel of Firmiana simplex is closed at first, then opens widely, later closes intimately, and again becomes widely opened. 2. Coalescence of the two rims of a single carpel is by means of close approximation, cell division, and cell enlargement. 3. Development of additional sutural tissue is brought about by the activity of the cells at either margin of the carpel, which meet and then divide tangentially to the suture. 4. Coalescence of the carpel margins also is due more or less to the enlargement and division of the cells of the two placental bundles. 5. No trace of former suture can be observed in the tissue after coalescence. 6. The carpels open by mechanical breaking. This breaking ruptures individual cells, indicating that the former opening has been completely eliminated. 7. Coalescence of the stylar regions takes place before pollination, and later the entire style withers and is broken off. 8. The stigma is derived from the top and adaxial surface of the sporophyll.