Development of stomata in some Papilionaceae
The ontogeny of stomata is described for 20 species of Papilionaceae. The mature stomata may be paracytic, anisocytic, anomocytic, diacytic, or with one subsidiary cell. The different types occur individually, or are placed side by side even on the same surface of the leaf. In many species the paracytic type is by far the most common, but in some anisocytic or anomocytic types are more frequent than the other types. The diverse types of stomata show mesogenous development. An increase in the number of subsidiary cells takes place either by their division, or by the neighboring perigenes assuming the form of subsidiary cells. Contiguous stomata are normally formed from two or more adjacent meristemoids. However, in Lathyrus sativus, in which they are frequent, their formation by "budding" has also been observed.