Term:

Lower/upper septum
Definition:

Referring to the combined lengths of the lower and the upper septa as seen in longitudinal sections. The two septae are divided by a septal articulation. The lower septa gives rise to the placenta and the upper septum develops into the columella of the fruit.
Notes:

The two septae are divided by a septal articulation. The lower septum gives rise to the placenta and the upper septum develops into the columella of the fruit. The upper septum is sometimes lacking in indehiscent-fruited genera and best developed in species of Allantoma, Cariniana, and Couratari which have cylindric fruits and an opercula with long columella.