Abstract
The normal and the abnormal stomata on the leaf of Pteridium aquilinunt var. latiusculum were studied.
The normal stoma on the diploid or the tetraploid plant is formed as follows: a stomatal initial appears in the dermatogen; dividing once or twice it gives rise to a stomatal mother cell; a stomatal mother cell divides into a pair of cells; they develop into a pair of guard cells differentiated typically.
The persistent stomatal mother cell is rarely observable on all diploid and tetraploid plants. It remains undivided, circularly or elliptically shaped, and not thick-walled.
The epidermized stoma is rarely observable on the tetraploid plants. In this type a stomatal mother cell divides into a pair of cells but they develop erratically into the epidermis-like cells. They are not raised above the level of the epidermis. Each cell of the epidermized stoma has the wavelike shape, no thick wall and no pore between two cells.
The existence of the poreless multicellular stoma is restricted to three of the tetraploid plants. This interesting stoma is characterized by the following features: it is constructed out of many cells (three to more than ten) caused by the further divisions of two cells originating from a stomatal mother cell; guard cells are not differentially thick-walled; no pore is formed; guard cells are stained not so well with Lugol solution; the chloroplast number is variable and sometimes very few; not a normal stoma in structure and function is formed on these three plants. The tetraploid plants bearing this stoma exhibit many other deviations from the normal morphology and physiology. However, such deviations are not specific to three plants but appear on the other tetraploid plants.
Also the causes of the occurrence of these anomalous stomata were discussed.
The writer wishes to express his cordial thanks to Profs. Drs. M. Kumazawa and I. Harada of Nagoya University for their guidance and encouragement.
