Question

Describe the external and internal morphology/structures of the microphylls of Selaginella and the megaphyll fronds of ferns. Which one is effective at photosynthesis? Why?

Answer 1

Selaginella is a type of vascular plants and it falls under the family Selaginellaceae. Microphylls are a type of leaf which are very short like we can see in moss. Normally the the microphyll contains one single vein but in Selaginella the microphylls have branched pattern. They also contain scale like structure ligule, present on the upper surface of the leaves.

On the other hand, the green leafes where photosnthesis takes place is called megaphyll. The megaphyll of fern is called frond. Fronds are large and divided type of leaves. It is attachd with the stem through a stalk. The part of the stalk which contain the leafy area is called rachis and rest of the part which do not have the leafy part is calles stipe. The single part of the leafs are known as pinna and all pinna together called as lamina. Pinna can further divides to produce small leaflets and they are known as pinnules.

megaphyll fronds of fern will have more effective photosythesis. They are large and flattened in structure with increasing surface area for photosythesis.