Reduction of the staminal whorl is also not unfrequent in Trifolium repens and T. hybridum, and has been seen in Delphinium, &c.
The staminal nature of this pseudo-corolla is inferred from the occasional presence of anthers on it.
In other cases, however, he observed that the pollen grains occurred on the inner side of what we now know as the staminal tube.
In the staminal whorl especially it is common to find additional rows.
The staminal row is more liable to multiplication of parts than the outer whorls.
Thus in Cruciferous plants the staminal whorl consists of four long stamens and two short ones (tetradynamous).
In willows the change of pistils into staminal organs has been frequently observed.
It is sometimes difficult to say whether these structures are to be referred to the corolline or to the staminal row.
Many cases of what was considered chorisis are in reality due to the development of stipules from the staminal leaf.
The disk is frequently formed by degeneration or transformation of the staminal row.