The inflorescence structure of Kummerowia (Leguminosae)

Inflorescences of Kummerowia are compound and the component axes appear to terminate in a flower. In order to clarify whether or not the flower is truly terminal, inflorescences of Kummerowia were studied organographically, ontogenetically and anatomically. Four inflorescence phyllomes are usually produced immediately below the seemingly terminal flower and appear to be borne on the same axis. The second phyllome subsequent to the lowest one is located at right angles to the lowest one, and the third and fourth ones located opposite each other and at right angles to the second. The lowest phyllome is sometimes undeveloped in K.stipulacea. Ontogenetic observation revealed the presence of two abortive apiceS. Anatomical observation revealed that these two abortive apices remain rudimentary in the flowering stage. On the basis of the arrangement of these phyllomes and the presence of the remnants of apices, the structure of the component inflorescence axis in Kummerowia is interpreted as follows: the component axis branches off a lateral axis, which is reduced entirely in length, from the axil of the lowest phyllome, and terminates in an abortive apex; the lateral axis in turn branches off one lateral axis of the next order, which is also reduced in length, from the axil of the second phyllome and terminates in an abortive apex; the lateral axis of the next order produces the third and fourth phyllomes and is terminated by a flower. The flower, which seems to terminate the component axis, is therefore axillary in origin. The axillary branch of the lowest phyllomes occasionally bears two lateral flowers. The branching system of the inflorescence of Kummerowia is identical with that of an inflorescence of Lespedeza cuneata. Kummerowia and Lespedeza are continuous in characteristics of the inflorescence, indicating the relationship between the inflorescence of Kummerowia and the pseudoraceme of Lespedeza.