Archespor

In plants, the archespor is the sporogenic tissue, i.e. those cells inside a sporangium in mosses , ferns and seed plants that later develop into spore mother cells .

The cells of the archespora can be recognized early due to their abundance of plasma . In deciduous mosses , the archespor is a cylindrical layer that is formed by the outermost layer of the endothecium . The archespora can also occupy the entire interior of a sporangium, the archespora can be a row of cells or - in the case of seed plants - consist of just one cell.

In the pollen sacs of the stamens of the seed plants, the archesporal cells can be recognized early on in the ontogeny in the four corners of the stamen primordium: they are large, the cytoplasm is denser than the surrounding cells and the nuclei are larger. They stand in elongated, often crescent-shaped or plate-shaped rows.

In ovules -Primordium more are hypodermic cells for archesporium: They are bigger, the nuclei are larger, the cytoplasm denser. In crassinucellate ovules this is a small group of cells; in tenuinucellate ovules it is a single cell. In the former, the cells divide several times, forming parietal cells on the outside and sporogenic cells on the inside. In the latter, the cell matures into a single mega- spore mother cell .

supporting documents

• Arthur J. Eames: Morphology of the Angiosperms . McGraw-Hill, New York, 1961, pp. 138f., Pp. 290ff.
• Gerhard Wagenitz : Dictionary of botany. The terms in their historical context. 2nd, expanded edition. Spectrum Academic Publishing House, Heidelberg / Berlin 2003, ISBN 3-8274-1398-2 .