Glossary Details – Lecythidaceae

Glossary Details:

Title: Placentation of Lecythis poiteaui. Photo by C. M. Potascheff

Description: Cross-section of ovary of Lecythis poiteaui based on Mori and Bolten 8636 from Surinam. Note the 4-locules and that the septal units are expanded into arrowhead-shaped structures toward the center of the locules. The blue dots outline a septal unit which includes the arrowhead-shaped apex and the thinner stalk; thus, a septal unit is derived from the walls of two adjacent locules. In contrast, the two placental units in a locule are derived from the same locule.

Term:

Septal unit head

Definition:

The expanded apical part of a septal unit which includes the head proper and many include two septal unit head extensions.

Notes:

One-half of the septal unit is derived from one carpel and the other is derived from the adjacent carpel.