Question

Describe the internal structure of the funaria capsule.

Answer 1

The capsule is the terminal part of the sporophyte. The capsule is developed at the apical region of the seta. The capsule is covered by the calyptra.

There are three regions of the capsule, apophasis, theca and operculum.

1) Apophasis: This is the basal part which is sterile. There is thin-walled epidermis and there are stomata in this region. There is spongy parenchyma which makes the region of the neck which connect with the seta. The central region contains the chlorenchyma cells which can perform photosynthesis.

2) Theca: This is the spore-bearing region which lies in between the apophasis and operculum. There is single layer epidermis with stomata and more layers of cells in the hypodermis. There are spongy parenchyma cells which have the chlorophyll and can perform photosynthesis. The food is obtained from these cells and the water and other nutrients from the gametophyte, which makes the sporophyte partially dependent on the gametophyte. There are air spaces which also contain the green cells called as trabecular cells. There are spores sacs which are the cavity with outer and inner walls. There are spore mother cells in the cavity which produce haploid spores. The columella is the central region which has the parenchyma cells that help in the transport of water and nutrients.

3) Operculum: This is the upper dome-shaped region where there is more layer of cells. The outer region is called epidermis. There are constriction and a diaphragm. There is rim which separates the cells of operculum and theca. There is peristome which has teeth arranged in the form of a ring in the region near the diaphragm. The teeth are made up of the cuticle. There are parenchyma cells which are thin walled and placed inner to the teeth.