In this article we will discuss about the anatomy of marchantia with the help of a suitable diagram.
Internally, in a cross-section (Fig. 2.7A, B) the thallus is made up of two zones; upper assimilatory and lower storage zone. The assimilatory zone is narrow, it is made up of a single layer of air chambers which enclose assimilatory filaments. Each air chamber is like a room (Fig. 2.7B, C) with its vertical walls, floor and a roof. The chamber walls are one-cell thick plates of cells, with or without chloroplasts.
On the floor of the chamber are numerous branched assimilatory filaments, characterized by small cells stacked with discoid chloroplasts. The chamber roof is protected by the upper epidermal layer which shows discontinuity in the form of a pore in the centre.
The pore is not a simple opening, instead it is a barrel-shaped structure with nearly half the barrel projecting above the epidermis and the other half remaining in the cavity of air chamber. When viewed from above, the pore is more or less a circular structure (Fig. 2.7C, D, a). The lower end of pore is characteristic of different species, it may be circular (Fig. 2.7D, a), angular or even cruciate (Fig. 2.7D, c)
The storage zone is made up of cells, majority of which are parenchymatous and full of reserve products. Scattered amongst them can be seen mucilage- and oil-containing cells. Also are seen sclereids which are thick-walled and help to provide mechanical support. The cells of lower epidermis elongate to form rhizoids. Scales can also be seen attached to lower epidermis.
The apical growth is initiated by a transverse row of apical cells. Air chambers initiate very close to growing apex, their origin is schizogenous.
