– Vascular System:

Ancient and Primitive Vascular System


With my trial and error experiment is about the internal structure of vascular system and see how it works in Angiopteris evecta ferns.
Using a microscope to get a closer view of the internal structure, by using different magnifications. By using the blue dye to stain the internal cells to get a better clarity.

The vascular system comes in two forms one is primary, and another has both primary and secondary. The primary vascular systems is in primitive ferns where they haven’t evolved enough to form the secondary vascular system. The vascular systems form around the late Silurian period, where the first fossil plants appeared around about 430 mya.

With the primary vascular systems starting to evolved in primitive ferns, such a simple, but complex’s vascular system the ferns were extremely tall and slender. The secondary system developed later, when the earliest trees and confiners were evolving. Having an extra layer of vascular system helped to protect the primary vascular system, as the secondary vascular systems would wane and wax in each seasons.

The photo’s below are from the frond and upper stem of the Angiopteris evecta fern leaflet, were cut in a cross – sections, showing the primary vascular system.

With the series of photos done with blue dye was a simple experiment to see how the vascular system travel through the Angiopteris evecta fern.
The blue dye was heavy concentrated on the inside of the serrate edge, as for the midrib and the stem isn’t as concentrated. For the false veins in the leaves are the capillaries of the primary vascular system.