As is well known, the ribs of the Monotremata have only the central head, the capitulum. |
It is readily known by the numerous irregularly arranged scales at the base of the capitulum. |
The achenes produced by each capitulum are similar, possess a pappus of bristles that causes them to move upwind and a well-developed elaisome. |
The tuberculum and capitulum on each of the trunk ribs are separated only by a shallow concavity. |
After fertilization, several achenes are produced per capitulum, and seeds are wind-dispersed. |
It passes through the capitulum of the radius and the ulna and its coronoid process and radial notch. |